6. The method of claim 1 , wherein identifying the set of similar content items for a first content item based at least in part on the generated similarity values comprises: for each content item pair that includes the first content item and a content item other than the first content item, retrieving the similarity value generated for the content item pair.
6. The method of claim 1 , wherein identifying the set of similar content items for a first content item based at least in part on the generated similarity values comprises: for each content item pair that includes the first content item and a content item other than the first content item, retrieving the similarity value generated for the content item pair. 7. The method of claim 6 , further comprising: for each retrieved similarity value for the content item pairs that include the first content item and a content item other than the first content item, determining whether the retrieved similarity value exceeds a predetermined threshold, and in response to determining that the retrieved similarity value exceeds a predetermined threshold, identifying the content item other than the first content item.