The goal of this project was to evaluate an Internet platform, known as PCSO (Process of Collaborative Store Ordering), created by Retail@Link in order to significantly ameliorate collaboration between suppliers and retailers. Its evaluation has been based on quantitative data, gathered during the last months, such as sales, products’ deficiencies (known as Out-of-Shelf situations), stock measurements, and percentage of orders agreed, but also on qualitative elements, including interviews with sellers and questionnaires completed by PCSO’s users in some “Veropoulos” stores. These stores were selected as representative of the whole chain and comprised pilot stores using PCSO and stores using the traditional ordering procedure. The major factors, used to evaluate the system’s ability to provide solutions, are the number of products missing from the shelves and the percentage of products sold that were inside the agreed mix. Moreover, an issue that inhibits the system’s further use has been examined, namely the variations observed between real stock and the numbers that PCSO provides to users. In this project, we present the methodology for the evaluation of the system, the outcome results, the final conclusions derived and some proposals for the future use of this system.