If you’re a Comcast customer living in one of the many states where they’ve imposed no real limits on bandwidth usage for the last few years… enjoy it while it lasts.

During an investor call today (link via Ars), Comcast executive VP David Cohen said that he predicts bandwidth caps (or, as ISPs prefer to put it, “usage-based billing”) to be rolled out network-wide within the next 5 years or so.

The reason they haven’t done so already? They’re still working out exactly where they can cap things before they start getting phone calls — that is, before people start calling up to cancel. Meanwhile, making things more complicated tends to scare people away, so they don’t want to just offer up multiple plans/tiers — so before they make any changes, they need to find that plan that works for almost everyone.

“I would also predict that the vast majority of our customers would never be caught in the buying the additional buckets of usage, that we will always want to say the basic level of usage at a sufficiently high level that the vast majority of our customers are not implicated by the usage-based billing plan.”

So, the good news: Comcast wants to find a data cap level that consistently works for “the vast majority”.

The bad news: if you’re reading this, you’re probably something of an avid tech blog reader. The sort that… tends to use a little more bandwidth, from day to day. In other words, you may well already be outside “the vast majority”.

For reference: if Comcast starts their bandwidth caps at 300 gigabytes (as they have in the select “trial” regions where caps are already in place), my house would pass that cap nearly every month. That’s almost entirely just because of our moderate-to-heavy use of Netflix/Hulu — I’m not hostin’ leet warez over here or anything. And thats just with two of us, neither making any particular effort to watch things in HD. Once 4K streaming comes into the mix in a few years and Netflix/Amazon/et al. get more stuff worth watching, those caps are gonna burn up quick.

Comcast is already “trialing” data caps in select parts of Alabama, Georgia, Tenessee, and other states. If you go over the 300 GB cap in one of these regions, your next 50GB costs you an extra $10.