Q. I have an e-commerce site and use conversion coding through Google AdWords and e-Commerce coding through Google Analytics. When I look at AdWords conversions in AdWords, they never seem to match the number of AdWords conversions in Google Analytics. Which number is correct?
A. In short, they both are accurate and correct. The bottom line is that AdWords and Analytics, although both are Google products, handle attribution differently. To understand why there is a difference we need to start with the way these two metrics are recorded.
First let's look at how your site is coded to capture these conversions:
Google Analytics (GA) works via the JavaScript tags that are placed on every page of your website to capture referral information. In addition, on the receipt page that is displayed after a customer makes a purchase; a specialized version of the code is used to capture order information.
AdWords also uses JavaScript; however, the coding is only placed on the page that has the conversion point. For tracking sales on your e-commerce site, the AdWords conversion coding would be placed only on the receipt page.
Now, using the following examples, let's explore how these codes work to track conversions:
- Bill searches for "widgets" clicks on your AdWords ad, comes to your site, signs up for your e-mail updates and makes a $100 purchase.
- Bob searches for "widgets" clicks on your AdWords ad, comes to your site, signs up for your e-mail updates and leaves without buying. One week later, Bob receives an e-mail (properly coded for GA) from your company, clicks on your offer and makes a $100 purchase.
In both examples, once the visitor clicks on the ad, a cookie is set by AdWords and because this cookie is present at the receipt page, AdWords will attribute the $100 sale to the AdWords click. Well what about Bob? He last clicked on the e-mail, why is this sale credited to AdWords? The AdWords cookie persists for 30 days and any subsequent transaction, regardless of source, will be recorded in the AdWords interface as a conversion.
Google analytics, on the other hand, pays no regard to the AdWords cookie and only credits conversions to the referral information it captures. That is, Bill's purchase is credited to AdWords and Bob's purchase is credited to your e-mail campaign.
Is this a problem? No not really. Would Bob have bought if not for the original AdWords click? Probably not! In addition, Google Analytics will not overwrite AdWords as the source when a user returns from a bookmark or directly types in your URL.
So in essence both systems are working accurately, they just work differently. There are some other technical factors related to code loading on a receipt page that could also sometimes cause a simple transaction to record in one interface and not the other. For example; after making a purchase a customer could quickly close the receipt page, which could allow the Google Analytics code to fire but not the AdWords code.
If you'd like to dive deeper on attribution, please take these three steps:
- Read the blog post by our Director of Web Intelligence, Joe Teixeira, on multi channel funnels in the new version of Google Analytics.
- Add other AdWords conversion types to your site. In the example above you could add an e-mail sign up and add a value to that conversion.
- Add dynamic values to your Google Adwords Conversion coding. This really doesn't help answer your question, but it is a best practice and will help you better optimize your campaigns and keywords in AdWords.
