Patent ID: 8639575

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; generating, by the data processing apparatus, from the publisher logs publisher pageview data for each publisher site, the publisher pageview data for each publisher site specifying pageviews that occurred during a first time period and including pageview records, each pageview record representing one or more pageviews associated with a user identifier a during a second time period that occurred during the first time period; receiving, at the data processing apparatus, a segment definition for a publisher site, 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 that satisfy the segment defined by the segment definition; 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 associated with 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; determining a segment quality measure for the segment 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 segment quality measure for the segment.