I’m not an expert on the subject, but a discussion elsewhere reminded me of some tests related to tracking and fingerprinting. I believe it’s a nice starting point if you are interested or want to show others how much information can be used to track them.
Growing up, your IP was the great identifier, and I’m old enough that it might have been true for a good chunk of time. Hiding your IP is still important, but most companies don’t really care about you as an individual. Actually, the fact you are hiding you IP is just more relevant information to put you in the most adequate group. At the end of the day, I assume you are unique just because they have enough information to create a group with you alone.
… Apparently I am almost fully unique by my language settings alone. 0.00% of people have canadian english and japanese as their phone language. Of course this is just from their dataset but still, this was definitely very enlightening!