https://brave.com is another attempt at this. You can fill a 'wallet' and have Brave distribute it to publishers

EDIT: Brave also focuses on privacy and ad blocking. It's also already released.

Brave does a lot more than just that though - it's a full fledged browser built on Electron. On desktop I found it lacking, but on mobile it's an excellent option. A good compromise between the UI responsiveness of Chrome and the extensibility and privacy features of Firefox for Android.

I finally bit the bullet and downloaded it. It's a pretty seamless transition from using chrome. I'm really impressed.

Amazon is actually EXCELLENTLY positioned to build a cross-domain paywall, a distributed Spotify for the web. Bezos owns the Post and knows the space, they have tremendous mindshare among developers (so the actual paywall API would be trusted out of the gate, hell they could even throw around AWS discounts to incentivize the cost of integration), and they have a strong ability to negotiate: "no, you don't get your own terms because you think you're a big news site, you get paid at the same rates everyone else does, because we're the WalMart here and our word is law."

The only reason I can imagine they haven't done this already is that they're mired in endless bureaucratic debates about whether this should be bundled with Prime... -_-

Bezos owning the Post is actually an argument against Amazon ever being successful at providing a portal for different news publishers. Would you entrust your business to a competitor? Of course not.