Cost of Bandwidth for hosting sites

One of the many problems that comes with hosting a site is the cost of bandwidth.

Commonly, the cost is part of the cost of hosting the site. If something goes viral or bots come scraping, the cost goes up, or access is throttled, depending on the terms and abilities of the hosting service provider.

This problem discourages me making some sites more broadly accessible. I can't afford to pay unlimited amounts. I don't have time for real-time, 7/24 monitoring but finding out when I review the bill at the end of the month is too late.

I have several publicly available phone numbers. Anyone can call me from anywhere in the world. I don't have a similar problem with my phone bill because with the phone the caller pays, if it is not a local call.

The equivalent, for hosting a site on the Internet, would be for the client to pay for the bandwidth: no incremental cost for the person hosting the site.

This is obviously possible. The telephone companies implemented solutions for charging the caller long ago. Yet it has not been implemented on the Internet, as far as I know. All the hosting services I am aware of charge for bandwidth, with or without caps beyond which access is disabled.

ISPs already charge for bandwidth. Higher prices for unlimited bandwidth. Marginal prices for additional bandwidth. No change would be required to pass on the cost to the client/consumer.

What is missing is the mechanisms to transfer funds between the ISPs: from the ISP of the client accessing a site or service to the ISP of the server providing the site or service.

I hear vaguely about some deals for cost sharing with very large content providers, but it isn't routine, like it is with the telephone.

Even if it was routine, I would still be discouraged from making sites more widely available by security, privacy and IP theft concerns. But it would be nice to not have to worry about unpredictable, unaffordable costs if I host a blog, website or whatever.