It seems like marketers can't wait for the newest shiny product just so they can collect data about you to sell you more junk. I am surprised the computing community hasn't organized a software campaign to just poison these horrible "services" databases with so much junk data that they become unusable. I am not even against them collecting data on me. Hell, I LOVE being able to look at my phone and see a flight and if there are any delays. I love that my phone tells me when there is an accident to avoid. I am even willing to sacrifice a bit for ads that are relevant to me. I am however uninterested in any of this if it means that you are asking me to give you permission to abuse the power. The reason that google is so easy to trust is because they outline What they do with your data in clear terms. I still think that people should use client side encryption with their email, but honesty is going to go further and last longer than a short sighted money grab for user data.
You're right, it's nice to have some advantage for a bit of privacy abandonment. The problem with privacy: Its global level goes to the lowest willing member of the human species.
You're ok to give away some privacy, you get a TV with face-recognition. You get some advantage. I like my privacy. I own no phone, no tv, etc.
I come dine with you. I get face-recognized by your screen, parsed in whatever server, located, and spamed scary relevant ads about skin problem. And I get no advantage for it. It's like the privacy-concerned guy who used it's own mail server, and discovered 80% of his communication were on google server cause he sent mail to gmail users. The much one person is willing to abandon in term of privacy the most we all abandon un-willingly.