My ideal experience would be I load $20 into the browser somewhere like a wallet in one block (that could be a payment processor step). If I visit a participating page, it decrements my wallet $.01 or whatever.
The downside is the possibility of abuse and tracking by governments, which would have to be handled at the source, not the symptom.
You visit website A,A,A,B,C,D,A,A
At the end of the month, you send your entire 20$ randomly to one of the websites you visited.
This will level out everyone's contribution and reward websites with lots of traffic. It eliminates the need for micropayments.