This booklet synthesises findings from:

Academic & Peer-Reviewed Literature

Barton, B., Zlatevska, N., & Oppewal, H. (2022). “Scarcity tactics in marketing: A meta-analysis of product scarcity effects on consumer purchase intentions.” Journal of Retailing / ScienceDirect.
Furner, C. P., & Zinko, R. (2017). “The influence of information overload on the development of trust and purchase intention based on online product reviews in a mobile vs. web environment.” Electronic Markets, DOI 10.1007/s12525-016-0233-2.
Hmurovic, J., et al. (2023). “Comparative analysis of time-limited scarcity offers in online versus offline environments.” Cited in Highlights in Business, Economics and Management (2025).
Huijsmans, I., et al.“fMRI scarcity-desensitisation research: Neural mechanisms of consumer habituation to urgency cues.” ScienceDirect / Taylor & Francis
Journal of Retailing and Consumer Services. (2018). “Exploring consumers’ perceived risk and trust for mobile shopping: A theoretical framework and empirical study.” DOI 10.1016/j.jretconser.2018.01.017.
Journal of Retailing and Consumer Services / Elsevier. (2024). “Buy Now, Pay Later (BNPL) adoption and its causal impact on consumer basket size: A synthetic difference-in-differences analysis.” (n = 63,672 orders).
Kim, K. J., & Sundar, S. S. (2015). “Does Screen Size Matter for Smartphones? Utilitarian and Hedonic Effects of Screen Size on Smartphone Adoption.” Cyberpsychology, Behaviour, and Social Networking / Human Communication Research coverage (N = 130).
Kivetz, R., Urminsky, O., & Zheng, Y. (2006). “The Goal-Gradient Hypothesis Resurrected: Purchase Acceleration, Illusionary Goal Progress, and Customer Retention.” Journal of Marketing Research, 43(2), 263–291.
Lewis, M. (2004). “Free shipping thresholds and their behavioural effects on e-commerce transaction value.” Wharton School, University of Pennsylvania working paper.
(2024). “Purchasing in the digital age: A meta-analytical perspective on trust, risk, security, and e-WOM in e-commerce”.
Taylor & Francis / Journal of Management Information Systems. (2023). “The impact of small screens and visual clutter on mobile cognitive load, preference consistency, and decision accuracy” (3 experiments, n = 823).
Zhang, X. (2026). “The impact of mobile channel switching on purchase incidence: A cognitive load perspective.” Journal of Business Research, Vol. 208 (N = 3,395,722 observations).

Large-Scale Industry Reports, Benchmarks & Panels

Adobe Commerce / Adobe Digital Economy Index. (2026). 2025 Holiday Shopping Report and Direct Online Transaction Benchmarks (based on trillions of direct US retail visits).
Baymard Institute. (2025–2026). E-Commerce Checkout Usability & Mobile UX Research Benchmark Study (combining 272 moderated 1:1 tests, eye-tracking, 850+ checkout step evaluations, and 11,777-participant quantitative panels).
Baymard Institute. (2024). The State of Mobile Checkout & Form Usability (50 major e-commerce mobile sites, 5,200 manually assigned usability scores).
Baymard Institute. (2013–2023). Perceived Security of the Payment Form and Quantitative Seal Study (evaluating consumer trust badge interaction).
Boston Consulting Group (BCG) & Shopify. (2023). Leading Online Shoppers to the Finish Line: A multivariate logit analysis of checkout friction and express payment performance (220,000+ storefronts, 1B+ transactions).
Chrome Team / Google. (2024). Autofill performance and form-abandonment reduction telemetry research.
(2026). Digital Experience Benchmark Report (99 billion user sessions across 6,500+ global sites and 9 industries).
Google, Fifty-Five, & Deloitte Digital. (2020). Milliseconds Make Millions: How mobile site latency impacts retail, travel, luxury, and lead-generation conversions (natural pre/post cohort analysis of 37 enterprise brands, 30M+ sessions).
Google Research. Smartphone Use by Non-Mobile Business Users: Text entry latency and virtual keyboard motor cost studies (n = 243).
(2026). Post-purchase delivery-date consumer expectations survey (n = 3,461 US shoppers).
Spiegel Research Centre, Northwestern University (in partnership with PowerReviews). How Online Reviews Influence Sales: Longitudinal transaction tracking of Hammacher Schlemmer from zero reviews upward.
(2025–2026). Testing the conversion impact of 50+ global payment methods and BNPL integrations (150,000+ payment sessions under randomised holdback testing).
Zuko Analytics. Webform and Checkout Benchmarking Data (evaluating view-to-completion rates by device; 55.5% desktop vs. 47.5% mobile).

Merchant Case Studies & Controlled A/B Tests

Expedia Form-Field Case Study (Deloitte Digital). The financial impact of removing optional shipping fields on checkout validation and bank authorisation (reported $12M increase in annual profit).
Fabletics Checkout Optimisation Study (Smarty / Loqate). Address autocomplete implementation on new-customer order completion, showing international relative conversion improvements of +3.6% (Germany), +15.0% (Canada), +9.6% (Spain), and +1.6% (France).
Loop Earplugs Checkout Experiment (Convert). Randomised checkout personalisation experiment involving over 300,000 mobile users, documenting a -3.04% decline in completed transactions.
Official Vancouver 2010 Olympic Store (Elastic Path / Get Elastic).Single-page vs. multi-step wizard checkout A/B test (606 transactions, single-page won with +21.8% conversion lift).
Rakuten 24 Core Web Vitals Optimisation (Google web.dev). A/B test isolating the conversion impact of passing Core Web Vitals thresholds (+33.1% conversion rate and +53.4% revenue per visitor).
Ray-Ban Speculation Rules Performance Test (Google web.dev). Controlled mobile prerendering performance implementation, reducing LCP from 4.69s to 2.66s and yielding a +101.47% increase in mobile PDP conversion.

mobile optimisation

The Science of Mobile Shopping