Why There are Banner Ad Reporting Discrepancies

A discrepancy between DFP and analytics is to be expected because of the standing differences in reporting methodologies. DFP data is based on ad server logs and it is generally more accurate at reporting ad impressions than analytics data, which is based on cookies or page loads. Below are a few reasons that could account for discrepancies: - Different counting methodologies (server-based counting vs counting cookies or page loads) - Not counting the same thing: a click in Dart is not the same as an impression in analytics packages - In case of an ad in Flash with Internet Explorer, the Referrer Url is not provided and the origin of the user is then "blank". In this case, a user who clicked on a Flash ad in Internet Explorer would be, on the landing page, considered as having typed in the URL directly in the browser and analytics would not record the user as originating from another website. As about 70% of people use Internet Explorer, there can be a huge discrepancy. If you use Iframe for your ad call, you may have the same issue as the referrer will not be the site itself but the source of the Iframe, DoubleClick. Comparing Referrer URLs to DFP clicks is not a recommended practice as referrers in analytics aren't an accurate measure of clicks or landings for the following reasons: - Referrers can be disabled on most browsers. - Internet security applications can block referrer data. - Firewall and proxy servers can filter out referrers. - Users can set up referrer spoofing to prevent a site from knowing where they've been. - Depending on the ad type (rich media, standard image, etc.) and the ad tag (iframe, javascript, standard HTML, etc.) on the page, the referrer can be either DoubleClick or your site. In a nutshell, the numbers do not have to match because they are not counting the same thing. DoubleClick has a validated click counting methodology while Analytic packages work as a "page visit" tool. Unless your client is providing a Google Analytics Tracking URL (http://support.google.com/googleanalytics/bin/answer.py?hl=en&answer=55518) for their campaign, then the click data is not comparable.