If you are using Google Analytics to count conversions from Google Ads, you may be missing a large chunk of conversion data.
The reason why is because Google Analytics doesn’t do a great job at identifying website visitors who have come back to the site. It focuses mainly on session-specific data. This means, if a user clicked on an ad, didn’t buy, and then came back to the site directly the next day to purchase, Google Analytics will likely mark that person as “direct” traffic.
Another thing to watch out for when comparing conversion data across these two platforms is Google Analytics runs off different attribution models then Google Ads. Google Ads will look at the first click model so that you can make sure that if the user is going to come back and Google a brand name then you can properly attribute it to the proper campaign. However, Google Analytics will look at the last click or same day attribute. That means that it’ll show you that between this period and that period, this is what happened that day. Here’s an example, let’s say that Google Ads shows 1000 conversions and Google Analytics shows 800 conversions. There’s a 25% difference in conversions.
If you’d like to explore this further, here is our chief account strategist, John Moran, on the subject: