5. The method of claim 1 , further comprising: receiving a search retargeting segment that includes a set of search keywords; and estimating a deliverable inventory for the segment.
5. The method of claim 1 , further comprising: receiving a search retargeting segment that includes a set of search keywords; and estimating a deliverable inventory for the segment. 6. The method of claim 5 , wherein said estimating a deliverable inventory for the segment comprises: determining a deliverable inventory estimate for the segment for each cluster to generate a plurality of cluster-specific deliverable inventory estimates; and summing the plurality of cluster-specific deliverable inventory estimates.