This book constitutes the refereed proceedings of the 15th International Conference on Electronic Commerce, ICEC 2013, held in Turku, Finland, in August 2013. The theme of ICEC 2013 was "effective, agile, and trusted e-services co-creation" and reflects the alignment between computerized, formalized business procedures with the need to flexibly adapt and innovate businesses on the spot according to changing customer needs and requirements. The 13 papers published in this book were carefully reviewed and selected from more than 50 submissions, resulting in an acceptance rate of less than 25%. They are organized in topical sections on online advertisements and referential systems, recommender systems and pricing, social media, mobile services, business models, and societal implications.