At the beginning of March 2017, I decided to run an experiment: I would sign up to every single interstital that I encountered for a month. In this post I document this (quite frankly rather bonkers) experiment, and give insights into what I discovered along the way…
What is an interstitial (and do they affect SEO)?
Interstitials are those annoying same-page pop-ups that sometimes appear when you’re browsing a webpage. They appear for different reasons, but usually appear when you’re about to close the browser tab or if you scroll right to the bottom of the page/article. Most of the time (but not always) they’ll ask for your email details, to get you to join the site’s email newsletter.
As a user (and even as a marketer), I am infuriated by interstitials. I often wonder why people implement them, but have never actually gone to the effort of looking into their effectiveness as a sign-up tactic. Part of me just thinks “well, they’ve gotta work – otherwise people wouldn’t do them, right?” But then part of me thinks that I ignore them every time I see one, and I’ve even avoided websites that I know use them to the extreme…
Whatever the case may be, I’m even more curious about interstitials now – given that from mid-January, Google started to penalise them when used on mobile sites. So yes, they may help to get more people subscribed to your newsletter, but are they harming your website’s SEO efforts in the process…? Following on from the penalty rollout, Glenn Gabe (@glenngabe) had been keeping tabs on sites that had been using interstitials, but admitted that he had “not [seen] widespread impact” even “a full month into the rollout” (source; original emphasis). Even so, Google have this knack of scaring the crap out of webmasters whenever they pull stunts like this, and although it may be a case of the Baader-Meinhof Phenomenon in reverse(?), I’m convinced that I’ve seen fewer interstitials on websites since Google first announced and then supposedly implemented the change.
So for various reasons, I was curious: How many did I encounter every day? What form do they take? What kinds of sites do they appear on? I was about to find out…
The 30-day experiment
On 1st March 2017, I set up a spreadsheet to log all the sites where I encountered an interstitial during my usual browsing travels. Whenever I encountered one, I made a note of the page/site, the date & time, how it appeared and whether or not I was able to sign up. I’ve made a couple of changes, but I’ve made the spreadsheet public here if you want to take a look.
Vital Random statistics
In total I encountered 23 interstitials across 22 sites during the month (from 1st to 30th March). I honestly expected to encounter more than that to be completely honest… In fact, the inspiration for this experiment came from the fact that I’d noticeably encountered loads the month before.
20 of them were via desktop – only 1 was on a tablet device (iPad) and 2 happened while browsing a smartphone (iPhone).
The biggest gap I had between interstitial encounters was 8 days. The shortest gap I had was 5 minutes (or 0 minutes, if you count that I had two different kinds on the same site pretty much one after the other). And the most I had in one day was 4.
There’s a bunch of other stuff I discovered, too…