by Daniela Araujo
Part II: Tracking Revenue
Web marketing analysts are frequently puzzled when comparing stats between Adwords and Analytics. In Understanding Discrepancies Between Adwords and Analytics, Part I, I discussed the common causes of discrepancies in traffic reporting. In this article, I will discuss the differences in e-commerce revenue data reporting between Adwords and Analytics.
Conversion Tracking in Adwords and Analytics
Adwords and Analytics tracking codes work by placing a unique cookie on a user’s computer when the AdWords ad is clicked. Upon completion of an e-commerce transaction, the tracking code in the “thank you” page, along with the data in the cookie, allows Google to associate the completed sale with the ad that delivered the user to the site. Google then records the successful transaction, including its value and units bought. These conversion stats are updated every 3 hours in Adwords and every 24 hours in Analytics.
Causes of Discrepancies in Conversion Statistics between Analytics and Adwords
The following example illustrates 2 common causes of discrepancies between Analytics and AdWords tracking data:
While shopping online for dresses, Nadia arrives at dresses.com through one of it’s Adwords ads. After researching prices and styles on the site, she decides not to buy anything but she bookmarks dresses.com with an intention to return in the future.
Cause 1: Retroactive Crediting of Conversion by Adwords. Nadia returns to dresses.com 10 days later via her bookmark and makes a purchase. Both Adwords and Analytics successfully correlate the conversion with the ad that was clicked 10 days earlier. However, the Analytics system reports the conversion as having occurred on the purchase date, whereas the Adwords system will report the conversion with the date that the ad was originally clicked. This will cause a discrepancy in the daily reports generated by Adwords and Analyics and this kind of scenario can often create confusion for account managers (e.g., an ad which appears to convert long after it has been paused or removed).
Cause 2: Cookie Expiration. As noted above, Adwords and Analytics each place a cookie in the browser when an ad is clicked. However, there is one crucial difference between the cookies used by these tracking systems: the Adwords cookie is set to expire after 30 days, whereas the Analytics cookie expires after two years. Let’s return to our example to see how this may alter the conversion data.
Ninety days after clicking the Adwords ad, Nadia returns to dresses.com via her bookmark and makes a purchase. Analytics logs the conversion and properly credits the Adwords ad. The Adwords tracking cookie has expired, so the Adwords tracking system cannot correlate this conversion to an Adwords ad.
Cause 3: Time Zone. Discrepancies will result if Adwords and Analytics are configured for different time zones. Consider the effect of dresses.com having it’s Adwords account configured for Pacific Time and it’s Analytics account configured for Eastern Time. A transaction occurring on a Tuesday at 11pm Pacific will be reported by Adwords as a Tuesday conversion and Analytics as a Wednesday conversion.
In this installment of the series, I have discussed some common causes of discrepancies in revenue tracking between Google Adwords and Analytics. This is working under the assumption that both tracking platforms have been properly installed. It’s recommended that both AdWords and Analytics ecommerce functions be rigourously tested if major data discrepancies occur. Understanding how these tracking mechanisms differ helps alert account managers when spotting data discrepancies.