Even worse, how is the money distributed? Who determines the "worth" of a web site or other online resource, and then allocates them their cut?
The current free-market system with sites supported by ads isn't perfect, but it's like democracy - Democracy is the worst form of government, except for all those other forms that have been tried from time to time."
One can imagine (but probably not implement) a system where an ISP would maintain a "client access system" that signaled to compatible web sites that the user was willing to pay for content services. The signal would provide how much the user is willing to pay (to allow for ISPs to maintain different tiers) and the web site would, in return, defer ads and other annoyances for users who were willing to pay enough. Leave it up to the sites to say how much that threshold is, and leave it up to the ISPs to set the tiers and track the usage (like they dont do these two things already?) and lastly, divvy up the money. The free market still has a say in what sites are visited and what users are willing to pay.
But then the problems roll in: malware that forces site usage in the background. Sites that take your money but don't give a higher quality of service... And last but probably not least: users who have no idea how a system this convoluted works at all, and make very poor spending decisions with their capital.