My opinion is that caps make little technical sense, and I believe that the fundamental reason for capping is to prevent disruption of the television entertainment business model that feeds the TV screens in most households.
It’s common sense — if you are selling a service bundle to a household that includes a subscription TV service, it would make business sense if there wasn’t enough broadband capacity to replace it.
As of 2008, the Nielsen Co. says that the average American household consumes just over 8 hours per day of TV. To replace this with some sort of innovative and interesting new Over-The-Top offering, it would consume roughly 480 Gigabytes per month (based upon Netflix consumption at their current top “HD” rate.)
Keep in mind that this is the normative household TV consumption, so roughly half of homes view more than this! Add in day-to-day Internet use and clearly the 150GB to 250GB caps which are typical today are an effective blockade.
That said, note that bandwidth management is not used in our network. We upgrade links before congestion occurs.
the related links in his blog post are also excellent reading.