Carriers can be real jerks about data. Look at AT&T. They want us to purchase a compatible plan in order to use FaceTime on their cellular network. Okay. We understand that it eats up data, but the thing is that we have an allotted amount of data per plan anyway.
For instance, look at the new iPad on AT&T. 3GB of data will cost you $30. What difference is it to them if I want to use those 3GB on my iPad, or through tethering? Or if I want to use it for FaceTime? It’s still 3G, and they will cut me off when I’ve used it (or offer me more data for more money).
It’s the same with our cellular network. It’s data we are paying to use regardless, and we truly don’t think it makes a difference to them whether we use it for a FaceTime call or for a YouTube video.
Maybe we’re missing something here.

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It’s easy, the prices set for the data that we buy are done so with an assumption that x number of people will not use the whole amount. I wouldn’t surprised if the expected average of data usage is somewhere around half of that which is purchased. Something like facetime drives the average persons usage of their data up, and the higher usage breaks their pricing models. Anything that breaks their pricing models they will fight against and say that it’s unfair or unreasonable. It’s also the reason they made such a big deal about “Data Hogs”. Put simply those people were spiking the usage average and therefore eating into their margins because they were breaking the foretasted usage model. Is it right? no. Is it fair? no. It does however explain why they react and try to set the rules and policies that they do.
*thumbs up*