Suggestion: Offer Pre-Paid Data usage that doesn't expire!

No AT&T employees here.
No apple employees either.

We are just users like you.
For your particular suggestion-you need to contact AT&T.

I do like your suggestion though. Basically, if you want to use 3G AT ALL on any given month, they're guaranteeing themselves at least $15 for each of those months. It would be "fairer" to allow you to let the $15/250 Mb last until you've used up your 250 Mb. But, like most cell phone plans, the "minutes" don't roll over.

I like your suggestion, but I'm guessing that the carrier will not because they won't make enough money. Same reason they do not offer a similar plan for cell phones.

When you think of it, no one offers a plan Like Apollo_13 describes. Your cable TV provider doesn't care if your TV was off all month. You'll still pay the 95 bucks. Your phone company doesn't care if your phone was off all month either. You must still pay the full contract cost. No Internet service provider charges by data usage. The rates are fixed and only vary by the speed of the connection you buy. Doesn't matter if you don't go online all month. I think it helps keep the cost down, actually. If we paid by amounts used, then the costs wouldn't be spread out as much and it would end up actually costing more on a per megabyte basis. You might save some money on a low usage month, but use it a lot and you'd be paying a lot more than the fixed rates currently applicable.

Please note that the prepaid phone cards do not work for cellular service. Cell service is a very different situation. So your analogy doesn't directly apply. Your analogy of the the iTunes Store prepaid cards is even less applicable.

Anyway, if you want to suggest prepaid data plans, you need to make that suggestion to AT&T. It's not an Apple issue but rather is solely within the purview of the cell carrier.

Regards.

Again, you need to take this up with AT&T. It's completely up to them. There is no forum here that any provide any further assistance with this issue.