Structured data sets including one or more attributes are identified, each structured data set associated with, for example, a particular user. Values corresponding the at least one of the one or more attributes in each structured data set are identified. A condition established by a content provider, for instance, an advertiser, is compared to the identified values to determine if the condition is satisfied. When the condition is satisfied, one or more content items are identified to the users associated with the structured data sets containing identified values satisfying the condition.