Methods, systems, and apparatus, including computer programs encoded on computer storage media, for ranking devices based on a distance from a merchant device. One of the methods includes displaying, in a point-of-sale system, a listing of buyers located proximate to the point-of-sale system, the buyers having indicated using their mobile devices a desire to pursue a financial transaction in association with the point-of-sale system. The point-of-sale system determines relative distances of the mobile devices of the buyers with respect to the point-of-sale system and arranges the displayed listing in the point-of-sale system based at least in part on the determined relative distances.