Google Ads and Google Analytics handle the same data very differently. And for good reason: The two platforms have very different focuses.
Google Ads is focused on tracking 100% of the people who interacted with it and attributing those interactions to a sale.
Whereas Google Analytics, on the other hand, is simply a tool that has been developed to show you what's going on on your website...This means it's more focused on tracking where users came from immediately before converting.
Google Analytics doesn't care that the direct traffic will be high -- and that many of those conversions attributed to "direct traffic" could have interacted with Google Ads at some point on a previous session/day/week/month.
Google Ads does care about that. Because Google Ads wants to show you ALL of the conversions that it helped convert.
The reality is, before a customer converts, they usually go through multiple sessions first – they might click an ad, come back to your site the next day, and purchase on a different day.
Because of this, your conversion data can & will look differently depending on the platform you're using at the time.
Think of the platform like a lense for data interpretation: Google Analytics cares about sessions and Google Ads cares about ad interactions.
Google Ads and Google Analytics show different data 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.
If you'd like to understand the technical details of how this works, read on...
The Two Platforms Use Different Technology To Keep Track
The two platforms have different levels of tracking capabilities to recognize the same user across different channels, devices, etc:
Google Analytics measures session data using browser cookies. This is all it needs, since it's only looking at data that happens within a single session.
Google Ads measures session data using browser cookies, too. But it also uses IP address, session ID, and even WiFi. It also can recognize Google users if people are logged in on their phone or their Chrome browser and connect the dots that way.
With that said, Google Analytics’ method of storing data can often cause about 15-25% decrease in conversion value compared to Google Ads. In other words, Google Analytics drops data.
The Two Platforms Attribute Conversion Data Differently
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.
Even if the user clicked your ad, the credits would still go to “direct” traffic because it’s the last action the user took before converting. Why? Because Google Analytics uses the Last Click attribution as its default attribution model.
Depending on which settings your ad manager chose, Google Ads can use several different attribution models.
If a user clicked on an ad a month ago but only converted today, some or all of today's conversion will appear a month in the past – it all depends on the attribution model used.
As you can see, the two platforms almost always end up attributing conversions based on different rules (and attribution models).
Keep this in mind when using Google Analytics:
It is a tool that has been developed to show you what's going on on your website. It only sees where users came from immediately before converting, which means its direct traffic will be high since many people who interact with a paid ad will come back to the site directly when they're ready to convert.
If you’d like to explore this further, here is our chief account strategist, John Moran, on the subject: