The use of serendipitous cues to increase product advertising effectiveness on mobile short video platforms

Abstract

Mobile short video platforms have emerged as a dominant digital environment for entertainment, information consumption, and online shopping. Online short video platforms like TikTok, Instagram Reels, and YouTube Shorts rely on recommender systems to deliver a continuous stream of short videos, creating immersive and fast-paced consumption experiences. As these short video platforms integrate short video ads into users’ short video viewing streams, understanding how users respond to these ads has become a significant challenge for both theoretical and practical reasons. While recommender systems research emphasizes accuracy and congruence with users’ prior viewing behaviors, growing evidence suggests that predictable recommendations may induce fatigue and diminish user engagement. Against this backdrop, this thesis first reviews the existing research on serendipity in online shopping contexts to figure out the existing research streams and future directions. The thesis also examines how congruent and incongruent cues are in short video ads and short video stream themes. and how serendipitous cues of short video ads can enhance the effectiveness of advertising on mobile short video platforms. Empirically, the thesis employs a mixed-methods approach, combining a systematic literature review with two controlled experiments.

To be more specific, building on a systematic literature review of serendipity in online shopping contexts, this thesis conceptualizes serendipity not as a method of an algorithm, but as a user-perceived experience that is enhanced by the recommended short video ads. Prior research has shown that serendipity is associated with positive outcomes such as users’ satisfaction, curiosity, and purchase intention. However, existing studies mainly treat serendipity as an independent variable, offering limited insight into how users experience serendipity in online shopping contexts such as short video platforms. In particular, little is known about how cue congruence and cue incongruence, together with product novelty and shopping-goal relevance, shape perceived serendipity and influence marketing outcomes on short video platforms.

Therefore, to provide more research insights, Chapter 2 conveys a systematic literature review of serendipity research in online shopping contexts. Using PRISMA guidelines, the chapter synthesizes prior studies published in leading IS and Marketing journals and identifies three major research streams on serendipity: (1) serendipity as an algorithmic objective in recommender systems, (2) serendipity as a user experience in digital interactions, and (3) serendipity as a mechanism shaping consumer discovery, learning, and identity formation. The review highlights unexpectedness, novelty, and relevance as core components of serendipity in online shopping contexts. Meanwhile, this chapter also reveals three future research areas on serendipity related to users’ perception, changing role, and individual behaviors in online shopping contexts, such as short video platforms.

Based on the systematic review in Chapter 2, in Chapter 3, we conducted an online survey-based experiment that examines how short video theme and recommended products’ cue congruence versus incongruence influences product evaluation and purchase intention on short video platforms. The study manipulates cue congruency, product novelty, and shopping-goal relevance to test when and how congruent and incongruent cues can have more positive marketing outcomes. The findings show that under certain conditions, incongruent cues can have positive product evaluations, but only when the recommended product is both novel and relevant. Besides, for incongruent cues, shopping-goal-irrelevant but familiar products can also have better purchase intention. Similarly, with congruent cues, novel and relevant products receive the highest evaluations, while familiar and relevant products generate the strongest purchase intentions. Therefore, this chapter demonstrates that the marketing effectiveness of congruent cues and incongruent cues depends on the strategic alignment between cue congruency, product novelty, and shopping-goal relevance.

Based on the findings in Chapter 3, in Chapter 4, we conducted a laboratory experiment using a self-developed mobile short video application. This study conceptualizes the perceived serendipity as a psychological mechanism linking recommendation cues to marketing outcomes. Using incongruent cues as the basic condition, this research examines how product novelty, shopping-goal relevance, and exposure order influence users’ serendipitous feelings and the marketing outcomes. The results show that product novelty and shopping-goal relevance can significantly influence perceived serendipity, which in turn improves product evaluation. However, exposure order does not directly affect serendipitous feelings. Instead, in the exploratory test, exposure order moderates the relationship between perceived serendipity and product evaluation. Specifically, earlier exposure to recommended short video ads weakens the positive impact of perceived serendipity, underscoring the temporal sensitivity of perceived serendipity on streaming social media platforms, such as short video platforms.

Taken together, this thesis demonstrates that serendipity on mobile short video platforms can be effective under several conditions. Specifically, the perceived serendipity is enhanced by the strategic alignment among cue congruency, product novelty, shopping-goal relevance, and the exposure order within sequential, algorithm-driven online shopping contexts. By reviewing the past literature from Information Systems and Marketing, this research provides a detailed understanding of how serendipitous cues are perceived on short video platforms and offers a theoretical foundation for future research on user-experience-centered recommender system design and digital marketing strategy.

Date of Award	19 Jul 2026
Original language	English
Awarding Institution	University of Nottingham
Supervisor	David Phang (Supervisor), Jian Gao (Supervisor) & Jun Luo (Supervisor)