E-commerce solutions based on mobile devices have drawn great attention recently not only because it provides convenience to mobile users but also it generates revenue for service providers. However our study reveals that current applications failed in users' satisfactory because of three major issues: service availability, data accuracy and usability. Based on this discovery, we have proposed a solution, which is a middleware architecture that accommodates agents technology, service mash-up and a "contribute-reward" mechanism into a SOA. A model implementation has also been built for a mobile price comparison to test our proposed architecture and solutions. Results demonstrate the improvements on the issues addressed. © 2013 The Authors. Published by Elsevier B.V.