Patent ID: 8396746

Claim:
A computer-implemented method of selecting advertisements, comprising: at a client system having one or more processors and memory storing one or more programs for execution by the one or more processors: identifying first category information associated with a user profile of a user; preserving privacy of the user with respect to the first category information while obtaining a personalized selection of advertisements associated with the first category information, by: identifying second category information distinct from the first category information; requesting a first set of advertisements based on the first category information and the second category information from one or more first servers remote from the client system; receiving the first set of advertisements; requesting a second set of advertisements based on the second category information from one or more second servers remote from the client system; receiving the second set of advertisements; removing advertisements present in both the first set and the second set from the first set of advertisements so as to generate a difference set of one or more advertisements associated only with the first category information; and presenting at least one advertisement from the difference set.