I have a unlimited texting plan on all 3 of the cell phones that are with my contact on t-mobile. It costs like $30/month. For that I do get a fair bit of usage. On a good day I can send 1000 texts or more. [I text a lot ;)]. But have you ever wondered how much it costs for your service provider to process those texts? A lot less than they charge you thats for sure. The New York Times has a article about this and I suggest anyone paying that premium take a look at it.
[Source: NYT]
-Tracker