The fact you pay isn’t besides the point… it’s literally the entire point.
If a Starbucks did that and said “btw, the coffee is free”, there’d be a line out the door and half way around the block.
In fact, Starbucks does that and they don’t even give you free coffee. You use their wifi and next time you walk in they’ve got your fingerprint, if you have their app they have even more info, and people accept all this gladly for what? Free wifi and occasional rewards in the app?
You’re underestimating how much people value anonymity over privacy, and free stuff over both.
The Starbucks app will send you daily notifications and targeted ones, people do not care.
Has it ever occurred to people who are so anti-advertising that the reason we live in an ad driven world is because that’s what consumers want over just paying fair value for things?
Otherwise why would a paid alternative to gmail not exist? In fact, if people actually wanted that, why would Google not sell it to them? Google's accounts do not care if 10 cents comes from ads or from your pocketbook.