Most of the time, the data in AdWords and Google Analytics matches. However, in certain cases, it’s normal to have a certain degree of discrepancy. When there are major differences, though, you should take notice. You’ll need to determine the cause of the differences and, if possible, rectify the issue.
Measure the Differences
Before going any further, determine just how different the data is. Under the “Campaigns” menu, head to “AdWords Campaigns” and choose “Clicks.” A box with “Sessions” will appear with the option “Select a metric.” Choose the metric “Clicks.”
The report that appears will show you the difference between sessions in Google Analytics and clicks on ads. You can adapt the report to compare data from across all your campaigns and to look at individual campaigns.
As clicks and sessions are different metrics, you would expect some discrepancies. For instance, the same user may have clicked your ad more than once. However, if the gap between the two is extremely large, you need to investigate further.
Locating and Fixing Data Discrepancies
There are several common reasons for discrepancies. You need to consider each in turn to determine the cause in your situation.
Your AdWords account may not be linked to Google Analytics or you may be looking at a time period that includes data from before your accounts were linked. If your accounts are linked but no click or cost data is appearing, make sure that you have turned on the option to import data from from your linked account. Another possibility is that you have multiple AdWords accounts linked to the same Google Analytics view.
You may have filters that are removing some data from your Google Analytics reports. For instance, you need to bear in mind that AdWords filters any clicks that Google considers invalid — such as if a user keeps clicking on a ad to increase your costs of clickthrough rate. You pay nothing for these clicks, but Google Analytics still shows them as sessions.
There may be errors in your tagging. For example, manual tagging could have an incorrect configuration, AdWords destination URLs may be missing tags, or you may be using both manual and auto-tagging.
If auto-tagging is off and you never manually tagged your destination URLs with campaign tracking variables, traffic may appear as Google Organic rather than Google CPC. This will lead to significant discrepancies in your data. Your best option is to enable auto-tagging — if it will work for your site. Otherwise, add the correct campaign tracking variables to every destination URL.
Finally, make sure that destination URLs have either auto-tagging or manual tagging, not both. An exception is if you want non-Analytics tracking of AdWords traffic data. In this case, head to your “Property Settings.” Under “Advanced Settings,” check the box next to “Allow manual tagging (UTM values) to override auto-tagging (GCLID values) for AdWords and DoubleClick Search Integration.”
The GCLID parameter in destination URLs tells Google Analytics that traffic is from an ad. However, if users bookmark a landing page with the GCLID parameter, Google Analytics counts the traffic as coming from the ad. AdWords, on the other hand, does not count clicks, as the user is not clicking the ad. Similarly, this traffic costs you nothing.
Another issue impacting the GCLID parameter is server latency. If a user leaves the landing page before the tracking code executes, the GCLID parameter never reaches Google servers.
If you have a redirect in a landing page, code from Google Analytics may fail to launch. Therefore, Google Analytics will be unable to identify paid search traffic. Another issue related to landing pages is obstruction between the AdWords click event and the ability to load tracking code. Check that you have installed tracking code correctly and confirm that the web hosting servers are functioning.
Consider which of the above is likely to be causing discrepancies in your data. If possible, take steps to correct the issue. If the factor is out of your control, at the very least you will now understand why data appears different.