US Patent 8468083 Advertisement topic diversification and ranking

One or more first groups of one or more first content items are identified. A first score is determined for each of the one or more first groups. A second group of one or more second content items is identified. At least one of the one or more second groups correspond to at least one of the one or more first groups. A second score is determined for each of the one or more second groups. A third score is determined for the first groups and the corresponding second group based on the first scores and second scores. An adjustment is made to a ranking of the one or more first content items based on the third scores.