Abstract: Methods, systems, and apparatus include computer programs encoded on a computer-readable storage medium for providing content. A method includes: identifying a placement opportunity for content for a user device characterized as being included in a group in which the group is defined by a user having a specific attribute; providing a bid request to content sponsors, the bid request including characteristic information that identifies information known to a serving system about the user without specifying the attribute that is associated with the user; receiving conditional bids conditioned on the user having a specific attribute from the content sponsors that establish a price to be used in an auction for the placement opportunity; evaluating the received bids in view of the attribute associated with the user including using received bids in the auction to determine a content item for the placement opportunity; and providing a content item for the placement opportunity.

Abstract: Methods, systems, and apparatus include computer programs encoded on a computer-readable storage medium for providing content. A method includes: identifying a placement opportunity for content for a user device characterized as being included in a group in which the group is defined by a user having a specific attribute; providing a bid request to content sponsors, the bid request including characteristic information that identifies information known to a serving system about the user without specifying the attribute that is associated with the user; receiving conditional bids conditioned on the user having a specific attribute from the content sponsors that establish a price to be used in an auction for the placement opportunity; evaluating the received bids in view of the attribute associated with the user including using received bids in the auction to determine a content item for the placement opportunity; and providing a content item for the placement opportunity.

Abstract: The system has a collection of a plurality of objects. Each object defines a node in a k-partite graph, such that, the nodes can be divided into a number of mutually exclusive sets such that all of the nodes are in exactly one of the sets; further edges occur only between nodes in different sets; The system also has a simplification process that aggregates one or more of the nodes into one or more categories and identifies a category node corresponding to each category. The category node inherits the mode and the edges of all the nodes in the respective category. Further, the system contains Directed Acyclic Graphs Indices (DAGIs) whose nodes may have a 1-1 mapping with the nodes in the k-partite graph. These indices can be used to aggregate and hide nodes in the k-partite graph. Aggregation occurs by selecting one or more non-leaf nodes in the DAGI and aggregating all descendent nodes.