Patent ID: 8370202

Claim:
A computer-implemented method, comprising: accessing, by a data processing apparatus, publisher logs including data describing past impressions delivered for pageviews for publisher sites, the data including, for each impression: a user identifier; a publisher identifier identifying a publisher; a pageview value identifying a pageview; and a plurality of publisher key values of the publisher provided for the impression; generating, by the data processing apparatus, from the publisher logs publisher pageview data for each publisher, the publisher pageview data for each publisher comprising pageview records representative of pageviews that occurred during a first time period, each pageview record representing one or more pageviews associated with a user identifier and a publisher identifier pair during a second time period that occurred during the first time period, each pageview record including: a user identifier; a publisher identifier; and publisher key values provided for the impressions that occurred for the one or more pageviews represented by the pageview record; receiving, at the data processing apparatus, a segment definition for a publisher, the segment definition defining a segment by one or more publisher key values of the publisher; assigning, by the data processing apparatus, to the segment user identifiers from records that include publisher key values that satisfy the segment defined by the segment definition; determining, by the data processing apparatus, one or more segment characteristics based on the user identifiers assigned to the segment and the pageview records of the user identifiers assigned to the segment, the determining comprising: determining a first number of pageviews from the pageview records of the user identifiers assigned to the segment, the first number of pageviews equal to the number of pageviews having publisher key values provided for an impression that satisfy the segment definition; determining a second number of pageviews from the pageview records of the user identifiers assigned to the segment, the second number of pageviews equal to the total number of pageviews represented by the pageview records of the user identifiers assigned to the segment; and determining a segment quality measure that is proportional to a ratio of the second number of pageviews to the first number of pageviews; and providing, in response to the segment definition, response data describing the one or more segment characteristics of the segment.