First time seeing Contributor. This is interesting but… can you really use it everywhere, or do creators have to opt-in? I don't see pointed how Google sends money to authors.
The ads you see are generally the result of an auction. When you use Contributor it bids in that auction for you, and typically wins it for a small fraction of a cent.
Publishers generally don't have to opt in: if you're a publisher advertising with AdSense, and a visitor shows up who uses Contributor, they'll see "thank you for being a Contributor!" and you get a micropayment from them into your AdSense account.
(Disclaimer: I work for Google, on things completely unrelated to ads.)
I don't like ads but I still want to contribute to the sites so I just pay with contributor: https://www.google.com/contributor/welcome/
Disclosure: I work for Google but those opinions are my own.