Redirect fbclid requests to 'clean' URLs

[jonoaldersonwp]

Facebook recently added a tracking parameter to all outbound URLs. That means that, anybody who clicks to a wordpress.org URL from Facebook hits a URL which appends ?fbclid=xxxxx.

This is cache-busting, and also causes issues with our SEO + Analytics. If we're not actively using fbclid to measure Facebook marketing/conversion campaigns, then we should remove this parameter.

Specifically, we should redirect any request which contains this parameter to an equivalent request, replacing the parameter with #utm_medium=referral&utm_source=facebook.com&utm_content=social.

e.g., ​https://wordpress.org/download/?fbclid=12345-abcde should redirect to ​https://wordpress.org/download/#utm_medium=referral&utm_source=facebook.com&utm_content=social.

[jonoaldersonwp]

Twitter does a similar thing when AMP formatted content is viewed through their apps/ecosystem. It appends ?__twitter_impression=true to the end of the URL.

We should redirect requests like this to #utm_medium=referral&utm_source=twitter.com&utm_content=social

[dd32]

Something that will probably work, but needs some extra conditionals put on it, etc. redirect_canonical() doesn't have any useful filters for this scenario.

[dd32]

In 8399:

WordPress.org: Canonical: Redirect Facebook and Twitter tracking parameters to UTM fragments.

Fixes #3946.