Fair point, but it's not a restaurant and educating readers this etiquette would be really tough. How about pay for reading and refund if you think it's not worth your money? Would you do that?
I'm not sure that educating readers would be that difficult if you cater to a well-cultured audience, personally I like the approach of Smashing Magazine when you use an ad blocker:
If I ran a blog I would include the same element, some wording like "you know, creating quality content requires more effort than spewing clickbait, mind leaving us a tip to let us know that you appreciate our efforts?" and a flattr button.
Although your idea sounds like a good starting point for a website which caters to a massive audience (basically, every news website).
A simple method for that could be if the user closes the tab or navigates away before a fixed time period passes, such that it's clear they didn't have time to read much of the article, automatically cancel the payment.
It's not a bulletproof idea of course, can be gamed. Users could take a screencap, or copy-paste, before the timer is up. But that's probably not worth worrying about until the model becomes widespread.
http://i.imgur.com/YpuvdlX.png
If I ran a blog I would include the same element, some wording like "you know, creating quality content requires more effort than spewing clickbait, mind leaving us a tip to let us know that you appreciate our efforts?" and a flattr button.
Although your idea sounds like a good starting point for a website which caters to a massive audience (basically, every news website).