The platform-economy is taking economic prominence and some platform-ecosystems succeed to attract millions of members worldwide. The exponential development of those market-organizations has been linked with the implementation of mutual evaluation systems on their digital infrastructure: those systems - that often take the form of a 5-stars evaluation with a qualitative comment - are depicted as providing users with security mechanisms. A large literature already explores the organizational role of evaluation systems both within and outside traditional organizational borders. In the present article we thus investigate the role that evaluation systems play in the organizing process (ie order building process) at stake in the particular configurations constituted by off-line transactions [HC1] of market-organizations from the platform-economy. In such configurations, users that have transacted together have to evaluate each other ex post (through an evaluation system provided to them by an organizer) apparently with no possibility to build a compromise, neither apparent possibilities to impose a point of view about what is of value and what is not. However users may precisely value different aspects of the transactions. In such context, which order would prevail? By conducting a case-study on the French carpooling platform BlaBlaCar, we extant literature and uncover the process of order building at stake in those market-organizations. We pinpoint that effective evaluation system use (or rejection of use) explains the order that finally prevails on the platform, the latter being thus the outcome of a complex interplay between both ecosystem members’ and organizers’ decisions.