GTM quietly shipped "Tag Serving Path", you can now serve gtm.js first-party with a cloaked container ID
Heads up if you are running sGTM.
As of May, 5 the Web Container client in server-side GTM has a new Tag Serving Path field.
It lets you serve gtm.js (and gtag.js) through your tagging server with a randomized alphanumeric path that hides which container is being loaded.
So instead of:
https://www.googletagmanager.com/gtm.js?id=GTM-XXXXXX
you load:
https://yoursite.com/data/zxq7pm2r/
(where /data is your tagging server path and /zxq7pm2r is the auto-generated serving path).
The container ID is still in the query string of course, but the loader URL itself no longer screams "GTM", which is what most ad blockers pattern-match on. Some will still catch it via the ?id= parameter; others won't.
Few questions for who already tried it:
Did you measured a recovery in pageview counts after the switch?
The path is auto-generated when you add a container but you can override it. Anyone benchmarking whether a custom-rotated path performs better than the default?