WordPress tells you, if you look, that they use analytics that you can opt out of, and vaguely mention the opt-out can be found in your settings. That is the extent of the how-to.
Well, you won’t find the opt-out just by clicking on “settings.”
After you sign in to WordPress, click on “My Site,” then scroll down and click on “WP Admin.”
On the left of that page, click on the little human-from-the-shoulders-up icon, which is where you find the submenu for “users.”
Click on the icon, then, in the list that shows, click on “personal settings.”
On the left of the page that brings you to, click on “privacy.”
On the page that opens, drag the slider next to “Share information with our analytics tool about your use of services while logged in to your WordPress.com account” to the left to turn it off.
It is so easy, no wonder they very vaguely sort of almost but not really tell you where to find it.