12. A system comprising: a processor; a storage device coupled to the processor and configurable for storing instructions, which, when executed by the processor, cause the processor to perform operations comprising: receiving a set of actions indicating interaction with web content, the set of actions including scored and unscored actions where a scored action is associated with a known score of at least one property of a user associated with the action; inferring initial scores for the web content based on the known scores of the scored actions; estimating initial scores for the unscored actions; inferring revised scores for the web content and inferring initial scores for the web content only associated with the unscored actions based on the known scores of the scored actions and the initial scores of the unscored actions; estimating, by one or more processors, revised scores for the unscored actions based on the revised scores for the web content associated with the scored actions and the initial scores for the web content only associated with the unscored actions; inferring, by the one or more processors, revised scores for at least a portion of the web content based on the known scores of the scored actions and the revised scores of the unscored actions; and performing a plurality of iterations of the estimating and inferring steps above.
15. The system of claim 12 , wherein the at least one property comprises a demographic property.