I’ve done some digging and I think I’ve been able to get to the bottom of this.
tl;dr: It’s the Facebook pixel installed on the Monzo website triggering this.
The Detective Work
To work this out I first of all checked my off-Facebook activity and found it a bit odd that the last reported date was Saturday 25th January 2020. If the actual application was pinging Facebook then I’d expect that the date displayed would be much sooner to today as it’s the 84th of January and I’ve pretty much checked my balance every hour.
Next I decided to check how I was interacting with Monzo. On my MacBook I generally use Firefox and I use an add-on called Facebook Container to stop Facebook from tracking me around the web. On my Android mobile however it’s a different story. Whilst I don’t have the Facebook app, I am logged in on Chrome and I don’t have anything to prevent Facebook logging my data.
With that in mind I remembered that on Saturday I opened the email about our new overdraft rates and clicked through to view the terms and conditions.
There’s a brilliant little add-on for Google Chrome called Facebook Pixel Helper that shows you any Facebook pixels installed on sites you’re browsing. It’s useful for me as an advertiser as I can check that pixels have been installed correctly and are reporting back the required data.
Visit the terms and conditions page and access the tool and voila, one pixel found:
I had a look back at my browsing history on Google Chrome and I haven’t visited the Monzo website since the 25th which marries up with this perfectly.
As a sidenote Monzo don’t have their pixel installed on the community so no events are being logged from us using this site.
Why Do Monzo Need A Pixel On Their Site?
Quite simply it’s for advertising purposes. The pixel reports back Facebook users that have visited your site and it’s quite powerful data. You could for example create an audience of people who have visited the Monzo website within the last 30 days and then from that audience exclude a list of everyone who already has a Monzo account. You can then be pretty certain that everyone remaining is curious but hasn’t signed up yet so you could hit them with some pretty aggressive advertising getting them to sign up if you wish to do so.
You can also use the pixel to measure things like how many people signed up to Monzo as a result of a Facebook ad that was run, which is useful when it comes to fine tuning ad campaigns, budgets and targeting.
So in conclusion I don’t believe the Monzo app is contacting Facebook, but on the other hand visits to their website are triggering Monzo to appear in your off-Facebook activity log.