12. The method of claim 11 , further comprising: ranking for presentation to a user of the social networking system, content provided by the application in relation to other content of the social networking system based on the generated quality score; generating a quality score for each of a plurality of other applications linked to the social networking system; and ranking the content provided by the application in relation to content provided by the plurality of other applications based on the quality score of the application and the quality scores of each of the plurality of other applications.
14. The method of claim 12 , further comprising: selecting a threshold number of the plurality of other applications to appear in an application center or application store featured in the social networking system.