Here at Metric Theory, we’re big fans of Google Analytics. For SEM advertising efforts, GA is useful for setting up Remarketing and gaining insight into PPC’s role in the marketing funnel. For Facebook ads, there are a variety of cases where GA is especially useful, but there are also several data sets where you should use caution when looking at in GA.

Google Analytics can be an incredible tool for analyzing Facebook. Image via Pixabay.

Google Analytics Facebook Benefits:

  • New Users: Very frequently, Facebook advertisers see the ability to introduce their brand to new visitors as one of the biggest wins of Facebook Ads. While we use all sorts of filtering for Facebook prospecting efforts, like excluding page fans and past site visitors, the best way to truly measure how many new visitors Facebook Ads are bringing to the site is the “New Users” metric in GA. This metric tells you how many completely new visitors your Facebook ads drove to your website.


  • % New Sessions: Similar to the New Users metric, % New Sessions tells you what percentage of total sessions driven by Facebook are from new users. This metric is informative for understanding how effectively Facebook is driving new visitors, and also for comparing Facebook to other channels. I frequently find that Facebook has a higher percentage of new visitors than any other channel, and you can also see how Facebook fits into driving new traffic to the top of the marketing funnel.

  • Bounce Rate: Facebook provides data on click-through rate, and once a visitor is on the site, bounce rate helps us see how effectively each landing page converts or engages visitors. Many Facebook prospecting efforts are not geared towards directly driving purchases, but rather introducing new users to the brand, so monitoring bounce rate gives you insight into how well a page is drawing users in. You can also explore bounce rates on landing pages outside of Facebook for inspiration on additional pages to test, or to understand how Facebook bounce rate compares to other channels.

Google Analytics Facebook Challenges:

While GA is helpful for evaluating new visitors, there are a few Facebook areas where GA is not as useful. Many of the Facebook challenges on GA come down to conversions and differences in how Facebook and Google Analytics tracks them.

  • Cross-Device Reporting: Unlike Google Analytics, Facebook automatically tracks people across different devices. Facebook reports conversions that occur on any device, so a user who clicks on an ad on their phone but later converts on their desktop is counted as a Facebook conversion. Google Analytics likely won’t recognize that this purchaser originated on Facebook, so Facebook doesn’t receive conversion credit. Cross-device purchases are particularly frequent among younger people, and for higher value items and products with longer click-to-purchase windows. We’ve seen advertisers who see more than 50% of purchases occur on a different device than the original click!
  • Day of Conversion Attribution: Facebook counts purchases back to the day a click initially occurred, whereas Google Analytics counts it to the day the conversion occurs. For example, if someone clicks an ad on November 20th and purchases on December 5th, Facebook would display it as a November conversion whereas Google Analytics would tally it in December. If you’re looking at a short period, you’re likely to see substantial differences in Facebook vs Google Analytics numbers.
  • Channel Attribution: Facebook defaults to a 28-day click and 1-day view format: all purchases that happen within 28 days of someone clicking on an ad, or within 1 day of them viewing an ad, will count as a Facebook conversion. Google Analytics attributes conversions to the last non-direct interaction. In the case of a Facebook user who initially clicked on a prospecting ad, then followed with a brand search on Google, and then eventually a conversion via a direct site visit, GA would give conversion credit to the SEM brand campaign, even though the original click occurred on Facebook.

Particularly for advertisers with an extended buying funnel, where purchasers change devices and touch multiple points in the marketing funnel, it isn’t uncommon to see GA revenue that is only a tenth of what is reported in Facebook. For this reason, you should generally avoid using Google Analytics to evaluate how well your Facebook ads are driving revenue or conversions. The Facebook Ads interface, or a third-party management platform, will typically have more accurate conversion and revenue data.

Metric Theory is a data-driven agency, and we always want to use all the tools at our disposal. Keeping these GA tips in mind helps us utilize the analytics features that are important for Facebook advertisers, while using other data sources when appropriate, to drive even stronger performance.