A common question asked by marketers today – Why is there a big difference between Adwords conversion revenue and Google Analytics Paid Search conversion revenue?
Below are a few reasons why there will be a difference.
Google Adwords:
Google Adwords has a cookie expiration of 30 days.
Google Adwords matches conversions to clicks.
Google Adwords campaign attribution cannot be overwritten by other traffic sources.
Google Analytics:
Google Analytics, by default, has a campaign cookie expiration of 6 months.
Google Analytics matches conversions to visits.
Google Analytics campaign attribution is overwritten by the most recent campaign visit (by default), excl. direct traffic.
Scenario:
A visitor clicks on a Google Paid Search text ad on 19 July and does not make a purchase. The same visitor, using the same PC and browser returns to the website 2 days later by typing the website address in their browser and makes a purchase.
Outcome:
Google Adwords: Records the conversion at click-date, 19 July.
Google Analytics: Records the conversion in the visit which resulted in the transaction, 21 July.
* Even if Google Adwords is linked to Google Analytics, Google Analytics will assign the conversion to the date of the transaction (the visit in which the purchase occurred), not the original date the ad was clicked.
Scenario:
A visitor clicks on a Google Paid Search text ad on 15 June and does not make a purchase. The same visitor, using the same PC and browser returns to the website 35 days later by typing the website address in their browser and makes a purchase.
Outcome:
Google Adwords: Does not record the conversion, as the conversion occurred after the cookie expired.
Google Analytics: Records the conversion in the visit which resulted in the transaction, 19 July. (35 days after 15 June)
Notes: Adwords has a cookie expiration of 30 days. Google Analytics, by default, has a campaign cookie expiration of 6 months. This can be amended, using the _setCampaignCookieTimeout() method. More information relating to changing the length of the cookie here: http://code.google.com/apis/analytics/docs/gaJS/gaJSApiCampaignTracking.html#_gat.GA_Tracker_._setCampaignCookieTimeout
Scenario:
A visitor clicks on a Google Paid Search text ad on 19 July and does not make a purchase. The same visitor, using the same PC and browser returns to the website 2 days later, after clicking on an email, which is tagged with _utm tags.
(Utm Tags: http://www.google.com/support/analytics/bin/answer.py?answer=55518)
Outcome:
Google Adwords: Records the transaction on 19 July (date of click), as the conversion occurred during the 30 day cookie period.
Google Analytics: Records the transaction, but it is not attributed to Adwords. By default, the most recent campaign (email campaign) receives credit for the conversion, although this can be amended.
Understanding the differences between Google Adwords and Google Analytics will help you understand why each platform is reporting different revenue.
