There's a new "experimental feature" being tested in Firefox 83: sponsored sites in the URL bar.
"Mozilla works with advertising partners to place sponsored tiles on the Firefox home page (or New Tab) that would be useful to Firefox users. Mozilla is paid when users click on sponsored tiles."
You can disable this by setting `browser.newtabpage.activity-stream.showSponsoredTopSites` to `false`.
Found via https://old.reddit.com/r/firefox/comments/jybx2w/uh_why_is_firefox_showing_me_sponsored_links_in/
@andreas not that I don’t believe this, but I am dumbfounded. If this is true, then Firefox is already dead, and we are just waiting for its corpse to cool completely.
"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko