Stats Snapshot: Counting Unique Users

By Carla Rover • May 12, 2011 •

According to a new report by MediaMind, conventional audience measurement metrics that do not adjust for user cookie deletion overestimate the number of unique users by up to threefold. MediaMind’s method of measurement, the adjusted unique, divides the number of total impressions by the average frequency of cookie deletion. The study was based on 26 billion impressions served in the U.S. and Europe from January to December 2010.

Other key findings include;

U.S. advertisers need 50 million impressions to reach five million users, and 200 million impressions to reach 18 million users.

Americans and Canadians delete cookies more than Europeans.

The English spend more time with rich media ads than any other group surveyed, an average of 60 seconds.

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