Many marketers try to reconcile impressions or clicks between their publisher implementation and their own Google Analytics, these two products measure different metrics at different points in the user funnel and so there are many places where they simply do not count the same action. This can result in a significant discrepancy between the publisher and analytics solutions, including Google Analytics.
If you see significant discrepancies (>10%) between the reports in your DoubleClick for Publishers (DFP) account and those in Google Analytics, keep in mind these important points:
- Referral data could be disabled (i.e: Internet Explorer, which is still widely used).
- Internet security applications and ad blocking can block referrer data.
- Firewall and proxy servers can filter out referral data.
- Users can use spoof data to prevent on site tracking.
- Depending on the ad type (rich media, standard image, etc.) and the ad tag (iframe, java-script, standard HTML 5 etc.) on the page, the referral could show as another provider.
- Google Analytics tracks page views, while DoubleClick for Publishers counts ad impression, two very different metrics.
If you’ve placed your Analytics code towards the end of your page, in very rare cases, a user enters and then exits a page before the page completely loads and before the tracking code is executed. In this case, DoubleClick for Publishers might count an ad impression, but Analytics doesn’t count the pageview. This would result in a higher impression count in DoubleClick for Publishers than pageview count in Analytics.
Google recommend that you don’t compare Google Analytics and DFP numbers due to possible discrepancies.