To Flat or to Cap?

No that's not a question about Australian coffee tastes and the critically important difference between a flat white and a cappuccino. This is a question about the differences in ISP retail models for broadband Internet access and the choice between a retail model of a "unlimited" flat fee that has no volume component, and a "capped" model where the service fee provides for a certain data volume and when that volume is reached either the user is exposed to an incremental fee, or the service is throttled back to a narrowband service for the remainder of the billing period. It seems that this is once more a critical question in the ISP world, and maybe this time the topic is best approached through television.