While consumers are shifting towards online clothing purchases globally, South Africa, a developing economy with well-developed infrastructure, is lagging in this regard. This research highlights significant drawbacks that may jeopardise the growth of online shopping despite the multiple advantages that consumers and retailers could benefit from. The key to the issue is that a consumer is not physically present in the store, and that online consumers’ experiences are limited to the technological capabilities of existing digital platforms. Inevitably, consumers’ online experiences would be framed in terms of what they are accustomed to in physical stores, therefore, sensory-rich, captivating environments. Creating well-designed mobile phone applications, which incorporate multiple sensory cues, is consequently crucial to capture online shoppers’ attention, and to ensure online retailers’ success. Millennials, the largest generational consumer group presently worldwide, is particularly important to online clothing retailers due to their potential buying power, interest in clothing as a product category, as well as their extensive use of mobile technologies. This study was conducted in the context of an emerging economy and aimed to examine the real-time influence of visual and auditory cues - that could viably be incorporated with available technology into a custom-designed mobile phone application for a fictitious clothing retailer - on millennials’ sensory experience and purchase intentions when purchasing clothing online. Clothing is a rather complex product category where sensory cues in combination with a range of extrinsic and intrinsic product characteristics are highly relevant during product evaluation. To accommodate the realities of physical store experience, three moderating influences were examined within the chosen stimulus-organism-response (S-O-R) theoretical framework, namely, the effects of telepresence, customisation, and available clothing product information. A positivistic, quantitative, descripto-explanatory, cross-sectional study was designed, presenting a two-phase electronic survey. It presented a vignette design that exposed respondents to the capabilities of the custom-designed mobile phone application before completing a questionnaire. Convenient, online snowball sampling through social media produced a sample size of 842 millennial respondents, from the Gauteng province in South Africa. Statistical analyses included descriptive statistics, covariance-based structural equation modelling, moderation analyses, and multivariate analyses of variance. The findings confirmed the significant influence of visual and auditory cues on millennials’ online sensory experience, as well as the significant positive moderating role of telepresence and customisation respectively, in facilitating millennials’ purchase intentions when shopping online. Failure to affirm the moderating influence of product information on consumers' purchase intentions, may be ascribed to the absence of intrinsic product characteristics such as fit, feel, and comfort, which are highly relevant but can not yet be incorporated into an online platform. This elevates the importance of how existing sensory cues are presented, and how they could counteract shortcomings of online shopping encounters. Considering what has been achieved by the gaming industry, in terms of visuals and sound when playing online, retail store mobile phone applications have not yet optimised their potential. Gender differences in online shoppers’ sensory experience, purchase intention and use of product information suggest that millennial men's purchase decisions may be more rational inclined compared to their female counterparts. The study indicates how millennials’ online clothing purchase endeavours could be enhanced in developing countries like South Africa, where online shopping has not yet reached first-world levels. Empirical evidence is also provided on how online sensory experiences and effective mobile phone app designs could enhance clothing retailers’ online apps to boost online sales. / Thesis (PhD)--University of Pretoria, 2021. / Gordon Institute of Business Science (GIBS) / PhD / Unrestricted