Google Tag manager firing Facebook pixel calls with appspot redirect URL

Question

We set up a tag in Google Tag Manager for Facebook conversion tracking, triggered by submission of a specific form.

Now we are seeing many conversions in the Facebook Ads console in times when we are quite positive not to have had any submission. Facebook tells us that the events come with this Redirect URL:

https://gtm-msr.appspot.com/render2?id=<OUR_ID>

These conversions come in groups of three (I mean, three such events at the same timestamps).

Has anyone experienced an issue like this? Any idea of a possible cause?

Answer 1

I've had a number of agencies tell me that my FB pixels had inflated or false data for the past few months. After some digging around Google I think what everyone confirms as a fix is to exclude traffic from that domain.

Simply put GTM renders an iFrame for non-javascript traffic. That iFrame is triggering the FB pixel and inflating the traffic.

Wrap your tags with this script to try and exclude traffic.

if (document.location.href.search('appspot.com') == -1) { 
}

That will block the GTM app from firing and return your FB traffic back to normal.