1. A method performed by an information server computer for communicating transaction proposals to a user, the method comprising: for each of a plurality of partners, storing, in a location accessible to the information server computer, partner data representing products available from that partner; receiving, at the information server computer, a request from a user for information related to a currently presented content item, the request including context data representing content of the currently presented content item; selecting at least one of the partners as a transaction partner, wherein the selection is based at least in part on comparing the context data to the stored partner data for the plurality of partners; obtaining at least one transaction proposal from each transaction partner; and transmitting a representation of at least one of the obtained transaction proposals to the requesting user.