Equivalent concepts expressed across multiple domains are matched and associated with a metapage generated by a social networking system. User preferences expressed on multiple domains, represented as pages in a social networking system, may be organized by concept and shared with advertisers, third-party developers, and other users of the social networking system using the metapages generated for the concepts. Aggregated social information may be presented to users of the social networking system viewing a page associated with a metapage. Information presented on external websites may be used to link pages across multiple domains with a metapage generated on the social networking system. A best page may be determined for a concept embodied in multiple pages on the social networking system using a hierarchy of rules. A best page may also be determined for a user based on information about the user.