Methods and systems for providing voice-mediated search capability to a mobile communications device involve receiving a signal from the mobile device that includes a representation of a spoken search request from a user of the mobile device, using speech recognition software to convert the search request into a text search request, extracting side information contained implicitly within the received signal, using the extracted side information to assign the user to a category, sending the text search request and the user category to content providers, receiving from the content providers content that is responsive to the text search request and the user category, and sending to the mobile device search results that are based on content from content providers. The methods and systems further involve sending searches and user categories to advertising providers, and sending advertisements returned by the advertising providers to the mobile device along with the search results.