Users of a social networking system are provided with advertisements when accessing content associated with the social networking system. The content of such advertisement may be generated by other users of the social networking system. An advertiser may provide an advertising template containing an advertised message and fields wherein a user can input an endorsement. The social networking system generates a user interface responsive to the template and provides the user interface to an endorsing user to receive the user's endorsement for the advertised product or event. The social networking system generates an advertisement responsive to the advertisement content provided by the advertiser and the endorsement content provided by the endorsing user. The social networking user can provide the generated advertisements to viewing users who meet the advertisement's targeting criteria and display criteria provided by the endorsing user.