Context-specific transaction proposals are automatically generated and presented to a user who expresses interest in a particular topic. A user viewing a World Wide Web page or other content item activates an interface to indicate that he or she is interested in additional information related to the subject of the page. A context vector or other representation of the content of the page being viewed is transmitted to an information server, which identifies possible transactions related to the content and proposes one or more of these transactions to the user. Transaction proposals can be presented together with a contextual search interface that allows the user to submit zero or more search terms together with the context vector as a search query.