If this happened, bittorent clients could get an automatic throttling feature built in to minimize downloading/uploading during peak hours, and maximize during off-hours.

This makes sense for heavy bittorrent users who are generally bright enough to realize how much data they are sending back and forth, but do you really expect casual YouTube viewers to know how much data is transferred when they watch a video? What about Grandma who wants to video chat with her grandkids? Graduated metered billing makes sense for certain things: electrical power, telephone calls, etc, but it doesn't make sense for Internet usage where there is no good way for users to easily get a handle on the amount of data transfered by their applications.

How is bandwidth used any more abstract than electricity used?

Grandma wants to video chat! She doesn't know how much bandwidth it uses! POOR GRANDMA!

Grandma wants to run the air conditioner! She doesn't know how much power it uses! POOR GRANDMA!

Maybe grandma should learn, eh?

You're being ridiculous. The marginal cost per kilobyte of data transfered during off peak hours is approximately $0.00. The marginal cost per kilowatt of electric power, while lower during off peak hours, is still material.

"The marginal cost per kilobyte of data transfered during off peak hours is approximately $0.00."

This can't be repeated enough when commenters -- as the above one did -- make such disingenuous arguments.

My ISP has a "Your account" page where I can view my current total bandwidth used for the month and the amount I have used each day. I have a much clearer idea of how much bandwidth I use than how much electricity I use.

I don't get the opposition to metered billing. You want unlimited use of a resource, but you don't want the provider to put conditions on how it used? With metered billing I have a reasonable expectation of getting what I paid for - ie. net neutrality. If my ISP broke net neutrality, it would mean that some of my gigabytes were intentionally served more slowly despite my paying the same price for them as any other gigabyte.

If my ISP wants to give preferential treatment to a particular site, it can do so in the form of financial discounts on the cost of using that site (which happens with content hosted by the ISP's own servers), all without affecting the speed of packets that I paid full price for.

They already do. Quotas (with peak/offpeak) are already common in some places, such as Australia.