Research Aim: The growth of eCommerce is increasing day by day. This research aims to find the factors affecting the online purchase decision. This study will provide a comparative analysis of eCommerce and m-commerce in the UK, focusing on different factors and characteristics of both. This study will differentiate the features of eCommerce and m-commerce and identify the main factors which influence the long run of online marketing to provide better services for consumers and make them know about new business opportunities.