• http://www.google.com/adplanner Wayne Lin

    For traffic measurement, Ad Planner primarily gathers data two ways. 1) Publisher using Google Analytics can opt-in their direct measured traffic statistics. 2) For sites that don’t opt-in data, Ad Planner estimates traffic using Google sample data, which comes from the sources mentioned in the article. Since we have direct measured and sample data, we’re able to build estimation models that triangulate between actual stats and estimated stats.

    More info about Ad Planner methodology:
    http://www.google.com/support/adplanner/bin/answer.py?hl=en&answer=175532

    –Wayne
    Product Manager, DoubleClick Ad Planner