No data plan with iPhone 4 AT&T?

I have been using a normal phone for years; I got a hand-me-down iPhone 4 the other day. I decided to cut down the sim card and stick it in the new phone. I'd heard that this automatically sets you up with a data plan, but I was willing to pay the price for data, even though I don't necessarily want it. But now when I'm off Wi-Fi and go to use the internet, I get this:

Could not active cellular data network. You are not subscribed to a cellular data service.

This leaves me with a few questions. Does this mean I in fact was not automatically signed up for data? Or does it mean I'm now paying for data but I can't access it because of something with my sim card? If it's the former, I'm fine with that and would rather not have data anyways. But if it's the latter, I need to know because I'd rather not waste money on a service I'm not accessing.

Correct, you have NO data plan right now, many older phones plans did not have a data plan. You might be lucky enough to be grandfather with your older plan.

I have the same sort of deal with t-mobile, I have a very old, no longer offered phone plan (pay on demand data) but have to pay per day I use cellular data. I just use free Wi-Fi thus have no need have any data charges unless I desire to.

  • Will the sprint iPhone Forever plan or a similar plan be available later this year? I don't have enough money right now and it expires soon, but I'm asking because it's a great deal and I don't want to miss out on it. Obviously you can't know for sure, but has anyone paid attention to previous years, and/or can you make an educated guess?
  • Will I be able to unlock my iPhone with a home phone plan instead of a wireless plan? I don't have a wireless plan with AT&T but I have a home phone plan does that count towards unlocking requirements? And also can I use a mildly cracked screen as a replacement screen on my iPhone?
  • What is data in a Verizon data plan? I just got an iphone 5 and am having some trouble. I know that data includes email, accounts and any internet websites (facebook, youtube, netflix). Does it use up data to have multiple internet browsers open even though I only look at one at a time? Is it possible to use up data when the phone is off? Also, is taking a picture, playing app games, listening to music, and siri considered to be "data" on the data plan? Is there an overall explanation for what a data plan is?
  • Is it cheaper to get a new iPhone on a plan or buy it unlocked and add a cheap plan? I can either buy the phone for $250 and pay a monthly $80 plan with data for 2 years or purchase the unlocked phone $800 and pay $30 - $50 a month - I might not get data but it wouldn't be a big deal to me, I'm just trying to find a deal thats not ridiculously expensive cause I can't really afford too too much right now. Which would be better?