Why are AdWords Conversion Tracker and Google Analytics showing different conversion rates and numbers of conversions? Which one should you believe? If these are questions you have ever found yourself asking, then you’ve come to the right place.

The short answer? They’re both right, although neither one is perfect. This is of course assuming you’ve set them both up correctly. How can this be? We’ll, I’ve attempted to put my unfortunate artistic skills to the test to try and clear up this puzzle.

So here’s the story:

Let’s say you have AdWords Conversion Tracker set up on a specific receipt page. You also have that page defined as a goal within Google Analytics. When you look in AdWords, you see that a specific ad campaign had 20 conversions at a conversion rate of 5%. When you look in Analytics, however, that same ad campaign was only responsible for 13, with a conversion rate of only 3%. Huh?

When you look at how the two systems track users and conversions, the answer to how this happens becomes apparent. Let’s look at two possible scenarios for a conversion:

Scenario #1: The user converts after clicking on an AdWords ad to get to the site.

secondvisitcomplete.jpgIn this scenario, all is well with the universe. In both cases, the user is said to come from the Google ad they clicked on. In this instance, a conversion will be registered in both Google AdWords and Google Analytics for the specific keyword.

Scenario #2: The user initially gets to the site from an AdWords campaign, but only converts later after coming back to the site from another source, like a Yahoo! organic search.

firstvisitcomplete%20copy.jpgHere’s where the differences become apparent. On the first visit from an AdWords ad, both Analytics and AdWords will set a cookie that marks the user as coming from the paid Google ad. However, if the user does not convert initially, but comes back a second (or third, or fourth) time from a different source (Yahoo! cpc ad, banner ad, email, etc.), things get sticky. Upon the return visit, the AdWords cookie will remain the same, but the Analytics cookie gets overwritten. If a conversion then takes place, it will show up in AdWords as coming from a keyword, but it will show up in Google Analytics as coming from the new source. Neither one is wrong, it’s just a different type of data.

So here’s the bottom line. Comparing the data in AdWords to that in Analytics is a little like comparing apples to oranges. AdWords will track users back to the initial keyword (only for google cpc sources), while Analytics will attribute conversions to the latest source (for all sources/keywords)The data not only might not be the same, but will not be the same.

So does this mean that AdWords will always report more conversions than Analytics? Nope. Because the Google Analytics cookie will not be overwritten by direct visits, if you have a site where someone who comes from AdWords can bookmark your site and return for multiple purchases, Analytics might actually report more conversions than AdWords.

Well, hopefully some of that made sense. Don’t expect the conversion numbers in AdWords and Google Analytics to be the same. They won’t be, and that’s ok.