Identifying users for advertising opportunities based on paired identifiers

摘要

An online system facilitates auctions for advertising presentation opportunities by identifying users associated with the presentation opportunities. The online system stores mappings between user identifiers and a plurality of partner identifiers used by advertisers to identify browsers. Partner identifiers are received from an advertising exchange and used to identify a user identifier corresponding to the received partner identifier. Using the identified user identifier, the online system identifies an alternative partner identifier associated with the user identifier and sends the alternative user identifier to an advertiser for use in selecting and bidding on advertisements. The online system returns the advertisers' bids to the advertising exchange with the partner identifier received from the advertising exchange. Converting a partner identifier to another allows advertisers to target a particular user while the online system protects the user's identity.