Will this just not make Google richer ?
This stops "sharing or selling of personal data", it does not stop use of data that has been collated by looking at & collating who does what on many, many web sites.
They will just say "we track everybody so we understand everything about everybody. GPC means that we cannot tell you anything, but we have new services that we can sell you that: do anything on your behalf & so let you do almost anything to anybody. So you will reap benefits of all our tracking of everybody (and we get lots more $$)" ?
If I visit a web site I kind of understand that they will learn something about me from that visit. What I do not want is:
* data from the many web sites that I visit collated to draw up a profile about me.
* the use of spooky/subversive techniques (more that just cookies) to identify me, eg abuse of ETags.
Maybe I do not understand but I think that this is naive and will not be much more effective than DNT ...