When you’re dealing with multiple sessions (meaning a website visitor came to the site more than once before converting) the conversion data can be displayed in multiple ways. This is called “attribution modeling.”
Google Ads and Google Analytics tend to use different attribution models because their purpose is different: Google Ads is trying to show us which ads are profitable, when, why, etc. Google Analytics, on the other hand, is trying to show us the most straightforward picture of what exactly happened on the site and when.
So, the two platforms almost always end up attributing conversions based on different rules:
- Google Analytics uses a same-day attribution model, whereas Google Ads uses whatever attribution model we have chosen based on the most logical way to analyze ad performance. Same-day attribution means the day that the conversion happens is the day that Google Analytics will show the data (conversion value, conversion rate, etc.).
- The attribution model we use the most often in Google Ads is time-decay. This means if a visitor clicked on an ad days before clicking on another ad and then converting, then Google Ads will split the conversion data between the first click (since that was the ad and date that did much of the heavy lifting) and the second click (since that was the ad that actually received the conversion).
There is a way to compare attribution models inside Google Analytics. This is useful if you want to see the conversion data from different perspectives all in one place and sorted by source. To get there, login at analytics.google.com, click on Conversions in the menu on the left. Then click “Multi-Channel Funnels” and then “Model Comparison Tool.” From here, make sure you have selected the date range, the conversion you want to see (i.e. transactions or contact form submissions, etc.) and then select at least two models. If you pull up “first interaction” as one of the models to compare, you will often see more conversions attributed to paid search than other types of attribution models. This is because a large percentage of leads tend to click on an ad, not purchase immediately, and then later type the website into the browser to make their purchase directly.
- Google Ads uses GTM, which attributes session data to browser cookies.
- Google Analytics (GA) measures session data by browser cookie, IP address, session ID, and even WiFi.
Our monthly reports include data from Google Analytics (as well as Google Ads) for two reasons:
- The first is to understand that there is more than one way to attribute this data in order to explain why your internal numbers won’t match up.
- The second reason is because one platform might have higher numbers than the other, so you would be doing yourself a disservice to only show one set.