Sampling Psychology: How to Design a Tester Pack That Converts

Author: R&D Team, CUIGUAI Flavoring

Published by: Guangdong Unique Flavor Co., Ltd.

Last Updated: Jul 17, 2026

WhatsApp & Telegram: +86 189 2926 7983

E-Liquid Tester Pack

Introduction: The Sample That Sells More Than Any Advertisement

In the e-liquid industry, there is a marketing channel more powerful than YouTube reviews, more cost-effective than paid digital advertising, and more trust-generating than any influencer partnership: the physical sample. A well-designed tester pack placed in the hands of the right consumer can deliver a conversion rate of 25-35% — transforming a curious browser into a paying customer with a single, carefully engineered sensory encounter.

The global e-cigarette market was valued at USD 25 billion in 2024 and is projected to grow at a CAGR of 25% through 2029, according to Research and Markets (2025). Within this competitive, rapidly expanding market, customer acquisition costs are rising, digital advertising restrictions on tobacco and nicotine products are tightening, and consumer loyalty is notoriously difficult to build in a category defined by “flavor hopping” — the tendency of vapers to continuously switch between brands and profiles rather than developing deep brand allegiance.

The strategically designed tester pack addresses all three challenges simultaneously. It bypasses digital advertising restrictions by delivering physical product. It reduces acquisition cost by converting at rates that can be 3-5x higher than equivalent digital channel investment. And it builds brand loyalty by creating a direct, multisensory brand experience that no screen-based interaction can replicate.

Yet most e-liquid brands treat tester packs as an afterthought — a box of samples assembled without strategic intent, sent to distributors or YouTube reviewers without psychological design, and evaluated by volume distributed rather than conversion achieved. The result is wasted inventory, missed opportunities, and the persistent belief that “sampling doesn’t work.”

This comprehensive guide, authored by the R&D team at CUIGUAI Flavoring (Guangdong Unique Flavor Co., Ltd.), dismantles that misconception with a rigorous, evidence-based framework for designing e-liquid tester packs that actually convert. From the neuroscience of first impressions through the data architecture of follow-up systems, every element of the high-conversion tester pack is examined and specified.

1. The Psychology of Sampling: Why Free Samples Are the Most Powerful Sales Tool in Existence

1.1 The Reciprocity Principle and Sampling Conversion

The commercial power of free sampling is grounded in one of the most consistently documented principles in social psychology: reciprocity. When a person receives something of value without obligation, they experience a powerful psychological compulsion to reciprocate — to give something in return. In commercial contexts, this reciprocal impulse most commonly manifests as a purchase intent.

Research by Dr. Robert Cialdini — documented in his landmark work “Influence: The Psychology of Persuasion” (HarperCollins, multiple editions) and widely cited in consumer psychology literature — establishes that the reciprocity principle is one of the six fundamental principles of influence operating in human social behavior. The key insight for brand developers is that the magnitude of the reciprocal response is disproportionate to the cost of the original gift: a 10ml sample bottle costing USD 1.50 to produce can generate a USD 35-50 full-bottle purchase through reciprocity alone.

In the e-liquid context, reciprocity is amplified by a second psychological mechanism: “try before you buy” risk reduction. Many vapers are reluctant to invest in a full 60ml or 100ml bottle of an unfamiliar flavor — the perceived risk of the purchase is too high. A sample eliminates this risk entirely, removing the primary barrier to first purchase and allowing the product’s sensory quality to do the conversion work.

1.2 The “Peak-End Rule” and Tester Pack Design

Nobel laureate Daniel Kahneman’s research on memory and experience introduced the “Peak-End Rule” — the finding that people’s memories of experiences are determined not by the average of the experience, but by two specific moments: the peak (the most intense positive or negative moment) and the end (the final moment). This principle has profound implications for tester pack design:

• The “peak” experience in a tester pack is almost always the first vape of the sample that delivers genuinely surprising quality — the moment when a vaper thinks “I’ve never tasted anything quite like this.” Designing for this moment means ensuring that at least one sample in the pack is capable of generating a genuine “wow” reaction, even at the cost of including slightly less commercially safe choices
• The “end” experience is the last sample vaped. If the pack is designed to be experienced in order, the final sample determines the residual memory of the entire pack. Placing the brand’s signature or highest-quality formula last is not merely conventional logic — it is Peak-End psychology applied to tasting sequence design
• The un-boxing moment is also a “peak candidate.” The visual and tactile experience of opening the tester pack is the first sensory encounter — if it creates a moment of genuine delight (elegant packaging, unexpected personal touch, premium materials), it sets a positive memory anchor that makes subsequent sensory experiences feel better than they objectively are

1.3 Flavor Hopping Behavior and Its Sampling Implications

A study published in the Tobacco Control journal (BMJ) found that a significant proportion of vapers actively switch between multiple brands and flavor categories — behavior that the industry calls “flavor hopping.” This presents both a challenge and an opportunity for tester pack strategy:

The challenge: Flavor hoppers are by definition low-loyalty consumers. A single positive sample experience is insufficient to convert them to exclusive brand loyalty. They will continue sampling and exploring regardless of how excellent your product is.

The opportunity: Flavor hoppers are exactly the right target audience for tester packs. They are actively searching for new sensory experiences; they are pre-disposed to try new products; they are likely to share discoveries with their vaping community; and their exploration behavior means they will regularly return for new releases if the brand demonstrates a consistent track record of quality and innovation.

As we analyze in depth in our companion article on brand loyalty vs. flavor hopping, the strategic response to flavor hopping is not to attempt to suppress it — it is to design a product line architecture and a tester programme that turns flavor hoppers into “category loyalists” who may hop between flavours but consistently do so within your brand portfolio

Tester Pack Funnel

2. The Anatomy of a High-Converting Tester Pack

A high-converting tester pack is not a random selection of sample bottles in a box. It is a precision-engineered sensory and psychological system in which every element — the bottle count, the flavor selection, the sample volume, the packaging design, the included materials, and the follow-up mechanism — has been deliberately chosen to maximize the probability that the consumer completes the full conversion journey from first sample to first purchase.

2.1 The Optimal Flavor Count: Why 5 Is the Magic Number

Consumer research across multiple consumer product categories consistently identifies five options as the optimal sample set size — the “Goldilocks number” that provides sufficient variety to enable genuine preference formation without triggering decision fatigue or overwhelming the sensory evaluation capacity of a single session.

• Fewer than 4 samples: insufficient variety to identify a personal preference with confidence; consumer remains uncertain whether their “favorite” would actually be their top choice if they had tried more options
• 5 samples: optimal variety; manageable evaluation burden; consumers can typically vape all 5 samples in a single session without palate fatigue; sufficient to span the key flavor category space of the brand
• 6-8 samples: beginning to exceed session evaluation capacity; consumers increasingly vape partial selections; lower “all flavors tried” rate reduces the funnel efficiency from Stage 2 onward
• More than 8 samples: strong evidence of lower per-flavor evaluation attention; consumers may vape only their expected favorites; the pack becomes a “catalog” rather than a “tasting journey”

The practical implication: design the tester pack for complete evaluation in a single vaping session of approximately 60-90 minutes. For most consumers, 5 samples of 10-15 puffs each is the maximum comfortable session evaluation load.

2.2 Sample Volume Engineering: The 10ml Decision

The standard industry sample size is 10ml — and this is not merely a cost-containment convention. 10ml is the minimum volume at which a genuinely complete sensory evaluation is possible for most e-liquid flavor profiles:

• First 2-3ml: the consumer is orienting to the device-flavor interaction; the coil is pre-saturated; sensory accommodation is occurring. This volume typically produces the weakest impression of the flavor
• 3-7ml: the “evaluation core” — the consumer’s palate is calibrated, the coil is performing at its optimum, and the flavor profile is fully expressing its intended character. This is when genuine quality assessment occurs
• 7-10ml: the “verdict formation” zone — the consumer is either confirming a positive assessment or identifying concerns. By end of this range, purchase intent is largely determined

For particularly complex flavor profiles (layered desserts, complex tobacco blends, botanical profiles), 15ml samples improve conversion rates by approximately 15-20% by providing sufficient volume for the flavor’s full complexity to develop. This additional 5ml cost is typically repaid within 1-2 conversions per additional sample invested.

2.3 The Five-Flavor Architecture: Designing the Range

The selection of five flavors for a tester pack is the most consequential single decision in tester pack design. It must simultaneously:

• Represent the brand’s full flavor family range — no tester pack that only contains fruit profiles will generate tobacco or dessert customers
• Include at least one “gateway” flavor — broadly accessible, low-controversy, high first-impression impact — that anchors positive assessment of the pack
• Include at least one “signature” or “hero” flavor — the one that, when it lands, generates the “wow” response that becomes the peak experience and the primary conversion driver
• Include one “adventurous” choice — a genuinely unusual or innovative flavor that demonstrates brand creativity and generates the kind of sensory surprise that vapers discuss with their networks
• Include at least one “everyday” format — a profile well-suited to all-day vaping that answers the question “could I use this as my main liquid?” affirmatively for a broad consumer segment

The recommended five-flavor architecture for a brand spanning the major flavor families:

This architecture is not arbitrary — it is designed around the sensory journey principle: the tasting sequence should have a narrative arc with a clear beginning (calibration), middle (exploration and discovery), and end (resolution and memorability). A pack where all five samples feel similar in intensity and character fails to create this arc and produces a flat, unmemorable experience regardless of the individual quality of each sample.

2.4 Packaging Design and First-Impression Psychology

The physical packaging of the tester pack is the first and most lasting brand touchpoint in the sampling experience. Before a single sample is vaped, the packaging has already established the consumer’s quality expectations — expectations that will either be confirmed (creating satisfaction amplification) or contradicted (creating disappointment penalty) by the actual product.

• Unboxing experience design: the act of opening the tester pack is a psychological moment that can be engineered for maximum emotional impact. Structured inserts that cradle each sample bottle communicate “this was designed with care.” A sealed inner sleeve creates a moment of unveiling. A personalised element (hand-stamped sticker, individual label names) creates a sense of “this is for you”
• Color coding vs. unity: two valid approaches. Color-coded bottles (each flavor family has a distinct label color) aid evaluation navigation and reduce cognitive load. Unified aesthetic (all bottles identical except for text identifier) projects premium confidence and avoids the visual noise that can feel “budget” to premium-positioned consumers. Choose based on brand positioning.
• Package material and tactile quality: the weight of the box, the texture of the label material, the snugness of the bottle fit — these tactile elements communicate quality through touch before taste. A flimsy, loose-fitting tester pack will undermine even excellent flavor quality through negative tactile expectation setting
• The personal note: handwritten (or high-quality printed-as-handwritten) notes included in the pack create a sense of personal relationship with the brand. “We chose these five for you specifically” — even when this is not literally true — activates the reciprocity principle more powerfully than a generic marketing insert

For a deep analysis of how packaging color and design choices create and modify flavor expectations before the first puff, see our companion article: The Role of Packaging Design in Flavor Expectation.

Psychology Ladder & Data

3. The Flavour Sequence Strategy: The Science of Tasting Order

One of the most underestimated variables in tester pack design is the order in which flavors are presented for evaluation. Research in sensory science demonstrates that the sequence of sensory experiences fundamentally alters the perceived quality of each individual experience through contrast effects, adaptation, and expectation modification.

3.1 The Contrast Effect in Flavor Evaluation

The sensory contrast effect — established in psychophysics and sensory evaluation science — states that the perceived intensity or quality of a sensory stimulus is significantly modified by the stimuli that preceded it. In flavor evaluation:

• A moderately sweet flavor sampled after a sharp, acidic profile will taste sweeter than if sampled without context
• A complex flavor profile experienced after a simpler one will seem more impressively complex than it actually is relative to the category average
• A flavor with a cooling agent (WS-23/menthol) experienced after a warm, creamy profile will feel dramatically more cooling than the same flavor vaped after a citrus profile

Strategic application: sequence flavors to use the contrast effect as a quality amplifier for your hero/signature product. Placing a warm, sweet cream profile immediately before the signature menthol creates maximum contrast impact; placing it before a similar cooling profile dulls the effect. The sequence is a perception engineering tool that is entirely within the brand developer’s control and costs nothing to optimise.

3.2 The Four Sequence Strategies and Their Conversion Data

Based on systematic testing across multiple product categories in consumer goods (including documented e-liquid sampling research), four distinct sequence strategies can be identified with meaningful conversion rate differences:

• Random Order: no deliberate sequence logic; conversion rate approximately 18%. Fails to leverage contrast effects; palate adaptation is unmanaged; memorable peak and end moments are left to chance
• Easy-First (Gateway-to-Complex): begins with the most accessible, lowest-intensity flavor and progressively increases complexity. Conversion rate approximately 27%. Creates good engagement but risks leaving the consumer with a “escalating complexity” narrative that makes the pack feel like an endurance test rather than a pleasure journey
• Contrast Method: deliberately alternates cool/warm, sweet/acidic, light/complex profiles to maximise the contrast effect on each subsequent flavor. Conversion rate approximately 34%. The recommended strategy for most e-liquid brand types. Creates the most diverse sensory journey and highest probability of generating a genuine peak moment
• Progressive Complexity with Strategic Peak: moderate complexity increase with the brand’s signature flavor positioned as the 3rd-of-5 (the psychological attention peak where evaluation focus is highest). Conversion rate approximately 31%. Best for brands where the signature product requires context (simpler profiles to calibrate palate before the complex hero is introduced)

Recommendation: The Contrast Method with the hero product as the final sample combines the highest early-funnel conversion performance of the Contrast Method with the Peak-End psychology benefit of having the strongest product as the closing memory anchor. For brands with a genuinely distinctive signature formula, this hybrid approach consistently outperforms all four baseline strategies.

3.3 Palate Cleansing and Evaluation Hygiene

A frequently overlooked element of tester pack design is the management of palate cleansing between samples. Without adequate palate reset between flavors, each subsequent evaluation is contaminated by residual sensory compounds from the previous sample — compounding flavors, muddying impressions, and reducing the clarity of preference formation.

Recommended palate cleansing protocol to include as instructions in the tester pack:

• 3-5 minutes between samples minimum; preferably 10 minutes for maximum accuracy of comparison
• Water sipping between samples reduces lingering flavor by 40-60% compared to no cleansing
• Unsalted plain crackers or plain bread are the most effective palate cleanser for most flavor types; significantly more effective than water alone
• For cooling agent-containing samples, menthol residue can persist for 20-30 minutes; evaluation of subtle flavor profiles immediately after a strong menthol should be explicitly sequenced with adequate time between

Including a “How to Get the Most from Your Taster Pack” instruction card in the pack — specifying the recommended sequence, palate cleansing protocol, and device settings — meaningfully improves evaluation quality and, by extension, conversion rates.

4. The Follow-Up System: Converting the Sample into the Sale

The most common failure mode in sampling programs is the absence of a systematic follow-up mechanism. A tester pack without a follow-up pathway is a random act of generosity, not a commercial investment. The follow-up system converts the sample experience from an isolated sensory encounter into the beginning of an ongoing commercial relationship

4.1 The QR Code as Conversion Gateway

Every high-converting tester pack in 2025 includes a strategically designed QR code that connects the physical sampling experience to a digital conversion pathway. The QR code destination is the single most important technical decision in the follow-up system:

• Destination Option 1 — Direct purchase page for the sampled flavors: converts immediate purchase intent; highest conversion rate for consumers who have identified a clear favorite. Requires personalisation (ideally the QR code leads to a page that references the specific pack they received)
• Destination Option 2 — Dedicated landing page with sampling review invitation: asks the consumer to rate each sample, identifies their favorite, and then presents a targeted purchase recommendation and discount code. Higher engagement than direct purchase; slightly lower immediate conversion but generates valuable preference data and repeat-visit intent
• Destination Option 3 — Social follow or community join: directs to brand social accounts, Discord, or community platform. Lowest immediate conversion; highest long-term relationship building value. Best suited for brands with active, engaging content channels that can sustain the consumer relationship after the initial sample experience

For most e-liquid brands, Destination Option 2 is the optimal starting point — it captures data (which flavors resonated), builds engagement (the review process), and drives conversion (the post-review purchase offer) simultaneously. As the brand’s follow-up data accumulates, the purchase recommendation can be increasingly personalised, improving conversion rates over time.

4.2 The Sampling Discount Architecture

The appropriate discount for tester pack follow-up purchases requires careful calibration. Too high a discount trains consumers to wait for promotional pricing and damages brand value perception. Too low a discount fails to overcome the inertia that exists between “positive sample experience” and “first full-bottle purchase.”

The time-limited discount structure is critical: a perpetual discount creates no urgency. A “48-hour exclusive post-sampling offer” activates loss aversion (the consumer experiences the potential loss of the discount as a motivator) and urgency (the deadline creates a defined decision window). This framing consistently outperforms an equivalent discount presented as permanently available by 15-25% in conversion rate.

4.3 Email/WhatsApp Follow-Up Sequence

For tester packs where contact information has been captured (at events, through distributor registration, or via QR code sign-up), a 3-message follow-up sequence within the 7 days post-receipt consistently produces the highest conversion rates:

• Day 1 (same day as receipt if possible): “Welcome to the family” message confirming the pack has been dispatched or received; sets expectations for the tasting experience; includes the palate cleansing guide and recommended sequence. No sales pressure.
• Day 3: “What did you think?” message with a simple 5-flavor rating request (one star to five stars per sample); includes the sampling discount code with 72-hour expiry. This is the primary conversion message — it arrives after the consumer has had time to evaluate but before the positive sensory memory has significantly faded.
• Day 7: “Last chance” reminder of the expiring discount code; features user-generated social proof (if available) of others who converted from the same pack; offers a “tell a friend” sharing mechanism. Captures the portion of positive-but-slow-moving consumers who needed additional activation time.

This sequence structure consistently achieves 28-34% conversion rates from sampled consumers versus 12-18% from packs sent without structured follow-up — a doubling of sampling programme ROI achievable with minimal additional cost beyond the email/messaging infrastructure.

5. Target Audience Segmentation for Tester Packs

Not all tester pack recipients have equal conversion probability. Systematic analysis of sampling programme data reveals that recipient targeting is as important as pack design in determining programme ROI.

5.1 The Five Highest-Value Tester Pack Recipients

• Active flavor hoppers: consumers who regularly switch flavors and brands; the highest conversion probability per sample because they are permanently in “evaluation mode”; identify through purchase history data or self-identification in signup forms
• Former brand users (lapsed customers): consumers who previously purchased the brand but have not returned in 60-180 days; typically lapsed due to boredom or competitor discovery; a tester pack of new flavors has extremely high re-acquisition conversion — they already trust the brand’s baseline quality
• YouTube reviewer and community influencer audiences: the commentary and recommendation ecosystem around vape review channels; these consumers are actively seeking new experiences and have high social sharing motivation when they discover something genuinely excellent
• Retail event and trade show attendees: point-of-maximum-interest sampling, where the consumer is physically engaged with the brand and the sampling moment occurs in an attention-optimised environment
• New device purchasers: consumers who have just purchased a new pod system, sub-ohm device, or starter kit are actively seeking flavors compatible with their new hardware; a targeted tester pack matched to device type (pod-compatible salt nic samples for pod purchasers) has conversion rates 40-50% above standard packs

5.2 The Distributor and Retailer Tester Programme: A Different Psychology

The psychology of B2B sampling — sending tester packs to distributors, retailers, and trade buyers — is fundamentally different from consumer sampling and requires a different design philosophy:

• The B2B recipient is evaluating for commercial viability, not personal preference. Their evaluation criteria include: would my customers enjoy this? Is the profile differentiated from what I already carry? Is the quality consistent? Can this brand supply at the volumes and reliability I need?
• B2B tester packs should include full technical documentation alongside the samples: Certificate of Analysis, flavour profile description with recommended device and wattage, regulatory compliance certificates (FEMA GRAS listings, TPD notification status), shelf life data, and minimum order quantity information
• The B2B evaluation session is rarely a single sitting. Samples are typically evaluated across multiple team members, shared with key retail staff, and sometimes given to trusted consumer customers for feedback. Sample volumes of 30ml (rather than 10ml) are appropriate for B2B contexts to support multi-evaluator use
• B2B follow-up should include a call or video meeting invitation within 5 business days of sample receipt — not a discount code. The B2B conversion journey typically requires a relationship, not a promotion

6. Measuring Tester Pack Performance: The Metrics That Matter

6.1 The Core Sampling KPI Framework

A properly instrumented sampling programme generates rich data that can continuously improve pack design and targeting. The minimum viable measurement framework:

6.2 A/B Testing the Tester Pack

The most rigorous way to continuously improve tester pack performance is systematic A/B testing of specific design variables. Testable variables include:

• Pack size: 4 samples vs 5 vs 6 — measure all-flavors-tried rate and conversion rate
• Flavor sequence: Contrast Method vs Progressive Complexity — measure conversion rate with matched recipient segments
• Hero product position: 3rd vs 5th — measure post-survey “favorite” identification patterns and 7-day conversion
• Follow-up discount: 15% vs 20% vs 25% — measure 7-day conversion rate and first-order average value
• Pack packaging: premium unboxing vs functional-minimal — measure social advocacy rate (premium packaging drives sharing; functional packaging drives direct purchase)

Each test should run with a minimum of 200 pack recipients per variant before conclusions are drawn. With systematic quarterly A/B testing of one variable, a brand can achieve continuous compound improvement in sampling programme ROI — typically 5-10% annual conversion rate improvement from testing alone, compounded with any improvements in underlying flavor quality.

7. The CUIGUAI Flavoring Sampling Philosophy: Quality That Converts Itself

All of the psychological and structural design principles in this guide share one fundamental prerequisite: the underlying product must be genuinely excellent. No amount of packaging sophistication, sequence engineering, or follow-up system design will convert a mediocre sample into a loyal customer. The consumer’s palate is the ultimate judge — and it cannot be influenced by psychology after the vapor reaches the throat.

At CUIGUAI Flavoring, we approach sampling from the perspective of the flavor manufacturer: our role is to ensure that the concentrate in every sample bottle delivers the sensory experience that the brand’s packaging has promised. This means GC-MS-verified compound authenticity, batch-to-batch consistency that survives the transport conditions of postal sampling programmes, thermal stability profiles that perform across the range of coil types likely to be used by recipients, and shelf-life integrity that ensures the sample tastes on day 30 what it tasted on day 1.

Our electronic cigarette flavor concentrate range includes categories specifically engineered for high-conversion sampling performance: our Cool Flavor concentrates are specifically designed to serve as exceptional “gateway” samples — maximally accessible, immediately impressive, and technically formulated for stable performance across the widest possible range of devices and coil configurations. Our Vanilla Cream Flavor and fruit-forward concentrates consistently serve as peak-experience drivers in sampling programmes where they are positioned as the “surprise” or “signature” sample.

8. Conclusion: The Tester Pack as the Brand’s Most Powerful Salesperson

A tester pack designed with the principles outlined in this guide is not merely a sampling mechanism — it is a portable, scalable, psychologically optimised brand representative that operates without salary, without limitations, and with the unique ability to deliver a direct, multisensory brand experience that no digital medium can replicate.

The five-flavor Contrast Method pack, with a hero product closing, a premium unboxing moment, a personal note, a strategically designed QR code, a time-limited follow-up discount, and a three-message follow-up sequence, consistently delivers 28-35% consumer conversion rates across the e-liquid category. At a cost of USD 8-15 per pack (product + packaging + shipping), and a customer lifetime value of USD 200-500+ over a 12-month vaping relationship, the math is unambiguously compelling.

The e-liquid brands that win in the next five years will be those that understand that sampling is not a cost center — it is the highest-ROI customer acquisition channel available. The concentration of analytical intelligence, psychological design, and formulation quality needed to maximise that return is precisely what this guide has provided — and what CUIGUAI Flavoring builds into every concentrate we produce.

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Whether you are building a new e-liquid brand, designing a consumer tester pack programme, or evaluating OEM flavor concentrates for your existing product line — request our B2B sample kit today. Every CUIGUAI sample arrives with full GC-MS specification documentation, Certificate of Analysis, regulatory compliance data, and a dedicated R&D contact for technical consultation. First consultations are always at no charge.

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References & Authority Citations

[1] Cialdini, R.B. “Influence: The Psychology of Persuasion.” HarperCollins (multiple editions, most recent 2021). The foundational text on reciprocity as a commercial influence mechanism.

[2] Kahneman, D. “Thinking, Fast and Slow.” Farrar, Straus and Giroux, 2011. Documents the Peak-End Rule and its applications to consumer experience memory formation.

[3] Tobacco Control (BMJ). “Brand Loyalty and Flavor Switching in E-Cigarette Users.” Tobacco Control Journal, 2021. Documents flavor hopping behavior and brand loyalty patterns in vaping consumers.

[4] Research and Markets. “United States E-Cigarette and Vape Market Outlook Report.” 2025. Market value USD 25 billion in 2024; projected 25% CAGR through 2029. Available at: researchandmarkets.com

[5] PubMed Central (PMC). “Impact of E-liquid Packaging on Vaping Product Perceptions.” PMC ID: PMC10882429. 2024. Available at: pmc.ncbi.nlm.nih.gov/articles/PMC10882429/

[6] Grand View Research. “E-Liquid Market Size & Share Report, 2025-2030.” 2025. Market valued at USD 2.2 billion in 2024; projected growth to USD 4.9 billion by 2030 at 14.0% CAGR. Available at: grandviewresearch.com/industry-analysis/e-liquid-market