I'm surprised that consumers haven't been charged this way yet. We're already offered different speed connections, which effectively limits the amount of data you can consume. And in the data center world, I'm charged for consumption. I don't see it being a big leap... however, it would have a silencing effect on some new technologies. Would it still be cost-effective for me to stream music or to watch all of Lost and Battlestar Galactica on-line? What would it cost me to Torrent a new Slackware ISO. Those are the things that concern me.

As a stop-gap measure, at least, I think it would be smart for major ISPs to run better caches and their own torrent nodes. If at least 2 of their customers want the same thing, then they can save on the backbone bandwidth (which is really the expensive part for them). This would also benefit consumers because there would be a nearby peer to exchange with. This was kind of the Tucows download model many years ago - but the data on your WAN so you don't have to download it over and over off the Internet. Content Delivery Networks like Akamai and Limelight already do this, to an extent.

RE: Charging by the Byte to Curb Internet Traffic: Financial News - Yahoo! Finance