While e-commerce can contribute significantly to the economies of developing countries, challenges may include a lack of telecommunications infrastructure, low Internet and credit card penetration, lack of skilled professionals and insufficient delivery systems. Cloud computing offers a solution to most of these challenges, providing access to a low-cost, reliable and flexible internet-based infrastructure. However, there is little empirical validation of the adoption of cloud computing in e-commerce; to bridge that gap, the present study proposes a cloud-based model of e-commerce adoption. Based on a survey of leaders of 175 small, medium, and large ICT firms in Egypt, a developing country where e-commerce is expected to boom in the coming years, the proposed model empirically validates organizational, technical and contextual factors that would make e-commerce adoption more effective for business, governments and service providers.