An online marketplace system generates an online marketplace for seller-financed transactions. The system includes a plurality of listings of transaction offerings that are available. The transaction offerings are listed by a plurality of users and are from a plurality of different categories of products and services. The transaction offerings include a plurality of transaction terms, including payment and seller-financing terms. A transaction engine facilitates the negotiation of transaction terms between users and the formation of agreement between users. Transaction coins are awarded during the successful performance of a transaction according to the agreed upon transaction terms. A reputation engine generates trust profiles and trust scores for users. The trust profiles and trust scores are used by parties to evaluate the trustworthiness of the other party. A user interface engine generates a user interface that includes listings from users and trust scores of those users.