Social web services have gained enormous popularity over the past years because of a steadily increasing demand for user participation in the whole web sphere. Social networks like MySpace or Facebook and media sites like Flickr or YouTube clearly demonstrate the variety and functionality of social sites. Significantly affected by this trend, online retail and e-commerce environments rapidly changed within the last years. Users were integrated into existing e-shops and mutated from simple buyers to fully integrated customers. Thus, a modern shop visitor can recommend products, leave comments, rate vendors or publish wish lists. This recent phenomenon, called social commerce or social shopping, leads to more customer satisfaction, user participation and social interaction. Accordingly, there is a strong demand for innovative social commerce models and concepts like crowdsourcing, consumer generated content or live shopping. This paper shows the results of an extended analysis of collaborative shopping networks and demonstrates the development of a representative interaction model. An evaluation of social commerce models gave insights into functionalities, interactions and entities of successful social web applications. To create a collaborative shopping network model, conventional web services as well as selected best practice cases were analyzed in detail. To meet the demands of modern consumers, success factors are presented in the final part.