Firefox doesn't have ad measurement and interests sharing built in yet (or am I wrong?) so it is very relevant for me. I would rather use black-and-white selects everywhere rather than having an advertising engine built into the browser.
That is disappointing. I went into settings to turn this off but it is already turned off and I don't remember whether I did it or my distribution ships Firefox with non-recommended settings. I hope it is the latter so that I don't get disappointed in Linux distributions also.