Google Analytics (GA) is a free tool offered by Google to track activity that occurs on your website.
With GA installed on a site, you can see how many visitors your website/app has, what pages receive the most traffic and, if configured, where actions occur.
For example, if you want to know how many users visit your site, Google Analytics can help you see the number of visits, what marketing channel they came from, and whether they were on a desktop or mobile device.
There’s no doubt that Google Analytics is an incredibly powerful tool for marketers, but GA was not built to tell you everything.
What Google Analytics Can’t Tell You
It’s important for marketers to be aware of Google Analytics’ limitations. Once you know what you don’t have, you can figure out how to get it.
Here are the five main things Google Analytics can’t tell you and how to get the missing information, so you can make the right marketing decisions.
1. Historical Data
Historical data is what happened prior to installing the Google Analytics tracking code to your website.
Think of the tracking code as a fishing net. Once in the water, you can look and see how many fish were caught.
But before the net is in place, you can only assume or guess as to how many fish passed through.
This is why I highly recommend setting Google Analytics up before your site launch. And, if you have yet to set up GA4, you should definitely make that a priority.
Another way you may be missing data is because Google Analytics (standard) does not automatically collect what actions users take on-site. It only tells you how many, where from, and what pages they view.
GA4 automatically tags some actions (known as events) but is missing some really important touchpoints for SEO pros, like submitting a form.
A good friend introduced me to a new analytics software, HockeyStack, which does not provide “historical data” per se but provides retroactive event tracking.
The moment you place the HockeyStack script, it automatically begins collecting all event data. No event tagging required.
I chatted with the co-founder, Emir Atli, who explained that even if it takes you months to get around to setting up goals and funnels, that historical event data will be there.
Here is a screenshot of what retroactive event tracking looks like in HockeyStack:
The second thing Google Analytics can’t tell you is another instance where you may be missing out on information about your site traffic: sampling.
Data sampling means that a smaller portion of data was analyzed in order to quickly identify patterns and trends.
Seer Interactive shared a great data sampling example years ago so rather than trying to reinvent the wheel, I’m going to share a paraphrased version.
Imagine your kids dump out 10,000 Lego pieces on the floor. For one reason or another, you wonder how many red Lego pieces there are.
Now, you could spend hours counting proverbial Legos – or you could select one section and count just 1,000 pieces.
If there were 200 red Legos in that 1,000 sample (this is a data “subset”), it’s reasonable to assume that 2,000 red legos were dumped out.
Obviously, sampling is significantly quicker. But at what expense?
In our Lego example, we assume that the red Legos are evenly distributed throughout the room. If the red Legos are not evenly distributed (as with business seasonality, for example) then your sampling may be way off.
So, what can we do about data sampling?
The first step is to know if your data is being sampled. If you are using the free Google Analytics account, data sampling kicks in at around 500,000 sessions within the specified date range.
When sampling is in effect, you will see a yellow shield with a checkmark at the top of the report. The message reads, “This report is based on N% of sessions.”