Following Comcast and others, another major ISP in the U.S. is playing with the idea of bandwidth transfer limits for their Internet customers. AT&T is considering imposing tiered bandwidth caps, with the intent of improving quality of service. They have tossed out some initial figures, with their lowest-priced packages coming with a 20GB limit per month and their highest-priced packages having 150GB limits.
These plans fall short of the 250GB limit Comcast has imposed. To avoid irate customers, AT&T has claimed they will contact people who exceed 80%. That would definitely be important, as once they hit the cap a customer can be expected to pay $1 per gigabyte for additional bandwidth.
While all of these companies make similar claims - that a small percentage of users consume most of the bandwidth - most of them blatantly ignore the fact that the Internet as a medium is changing. In a few years, streaming video is likely to be the norm, rather than the exception.