Context-aware applications adapt their functionalities based on users’ profiles and their current contexts. Complementarily, a trail is the history of the contexts visited by a user. Trails enable applications to explore the users’ past behavior. In this sense, trail awareness is considered an evolution of the context awareness, because applications explore an additional and more complete information source. This article proposes a model for trail-aware commerce support, called TrailTrade. The model uses the dealers’ profiles, contexts and trails to find deal opportunities and promote business transactions. Dealers may be people or companies offering and/or looking for something. TrailTrade supports the trade in goods and the exchange or sale of experience or knowledge. The model was implemented including an indoor location system and a deal assistant on mobile devices. The prototype was installed in a real environment and used to simulate a city composed of houses, a metro and a mall. This environment allowed a practical application in a scenario. This test evaluated the TrailTrade’s functionalities, mainly its trail awareness support. The results were encouraging and show potential for applying TrailTrade in real situations, fostering negotiations through the past behavior of dealers.