We already have proven, well defined method of DNT already: private browsing.
You are still being tracked with private browsing. You IP, user agent, OS, screen resolution, etc. are enough to connect the dots in most situations.
This is a decent idea that will need to be implemented to some degree if sites are eventually going to support under-13s, since it is illegal to track their behavior under current law. But you are right, I don't see a lot of places voluntarily signing up to make less money.
You are still being tracked with private browsing. You IP, user agent, OS, screen resolution, etc. are enough to connect the dots in most situations.
This is a decent idea that will need to be implemented to some degree if sites are eventually going to support under-13s, since it is illegal to track their behavior under current law. But you are right, I don't see a lot of places voluntarily signing up to make less money.