I use Google contributor, but only because I want something like this to succeed. I don't actually like the implementation they have. The biggest thing for me? I can't see where my money is going. At the end of the month, I want a breakdown of where my money went.

I want to know that when I went and visited John Smith's blog, he earned $0.13 from that visit. Contributing feels good when you know where your money is going. It's like a charity - you want to know your money went to a cause you care about. Right now I think Patreon has a better model, but I like the smaller increments that Google Contributor offers.