UPDATE: To answer a common question, if you put different subdomains, for example, in different profiles (now called views), all hits to subdomain pages outside the view you’re working in will show up as (not set). I see these pesky (not set)’s show up most commonly in content reports. However, if you have your subdomains (following the same example) in different properties, your other subdomains will show up as different sources altogether. These are called self-referrals and should be avoided like the plague. You can view these referrals by navigating to Acquisition > All Referrals and filter by your domain. View a screenshot of how to set this up, if you’re unsure. (Learn the difference between accounts, properties, and views from this Google resource.)
When I see a particular implementation error repeated over many clients, I take note and add it to my burgeoning Evernote list of blog post topics. It’s obvious that there is quite a bit of confusion around profile (now called view) filters in Google Analytics because I see where clients have shot themselves in the foot in analytics audits quite frequently.
What’s A Profile/View Filter?
No sense reinventing the wheel. Here’s what Google says:
Filters allow you to limit and modify the traffic data that is included in a view. For example, you can use filters to exclude traffic from particular IP addresses, focus on a specific subdomain or directory, or convert dynamic page URLs into readable text strings.
You can follow that link to learn all about how to set them up. And if regex (regular expressions) gives you the eebie jeebies, I wrote a simple guide for marketers.
I especially love using filters to rewrite ugly URLs. I once had a client who had so many different versions of their search listings page, it was impossible to analyze the effectiveness of the page to nudge visitors toward conversions. Here’s a screenshot of the filter I put in place:
Here’s the regex I used to consolidate thousands on pages into one /search-listings page:
I wrote this regex in 2008, when it was still pretty new to me. It could be simplified significantly. But as long as your regex is accurate, you’re not going to do any damage doing URL rewrites. Knock yourself out. Your content reports will love you for it.
How To Mame Yourself With Filters
The most common mistake I see — particularly with larger sites trying to avoid upgrading to Google Analytics Premium — is carving a site into sections with view filters without a solid strategy. Let me explain why this can push your data to the dark side in simple terms.
Imagine a box.
Your view filters are like a box.
Now imagine an adorable puppy in the box.
That puppy is like a visitor to one of your views. Your goal is to keep the puppy in the box throughout the entire visit (which Google is now calling a session). If you can’t do that, you need to revise your view filter strategy.
Why You So Mean To Puppies?
The puppy needs to stay in the box throughout the session because if it pops out of the box and then back in (and out and back in ….), every time it jumps back into the box, all of the data associated with that return is going to show up in your analytics reports as (not set). And (not set) shouldn’t be invited to any data party.
Example Of A Bad View Filter
Let’s say your site has three subdomains — www, blog, and store — and you set up a separate view for each of your subdomains. If someone clicks through to your store from a blog post and checks out, the landing page for that visit in the store view will show up as (not set). Why? Because the visitor landed on a blog page, and you have the blog subdomain filtered out of your store view. Anything that visitors do on your blog or main subdomain (such as read your About page) will be filtered out of the store subdomain’s view, leaving you with (not sets) all throughout your data.
On the bright side, at least (not provided) will have a buddy to hang out with.
Example Of A Good View Filter
Now let’s pretend you’re killing it so badly in your international marketing efforts*, you have three different versions of your site in three different languages, all on different subdomains. This would be a good candidate for a view filter because most visitors aren’t going to switch language preferences mid-session. Sure, you might have a super polyglot visit your site from time to time, but that risk for most sites is pretty minimal.
*If you’re not killing it in international, this is the marketer to talk to. She’s forgotten more about international SEO than I’ve learned. And she’s fluent in three languages. Yeah. That kid.
Simple Litmus Test
So before you go pinching off new views, you need to ask yourself, Would a visitor be able to jump in and out of this box in a single session? If the answer to that is yes, don’t do it. And if you do have multiple views, consider having one view that includes the entire site.