So 4GB a month would cost you 65 dollars. Which I guess is reasonably competitive with the 60 dollar a month MiFi plans with a 5GB cap (or compared with outrageous 10-15 dollar per day hotel wi-fi charges).
Of course large screen device data use is a very different beast than small screen use (lots more downloads, uploads and video streaming) so I could see people blowing past that 2GB in a heartbeat with their laptops tethered to their phones. But the 10 dollars a Gig overage charge plus the automatic you-are-reaching-your-data-limit notifications are a nice touch after years of carriers really sticking it customers on overages (my guess is they know if they don't start treating their customers fairly they will eventually be forced to do so by the FCC).
I am however concerned that this might lower the bar on people's expectations of media quality and potentially downgrade all of our online experiences as companies scramble to compress their products to fit these new limits. And if we are all worried about going over our quota that will have somewhat of a chilling effect on our willingness to willingness to explore new rich media. Lets just hope that as tablet and smartphone markets grow, and the carriers build our their infrastructure that the data limits will increase as well. Given the carrier's feet-dragging before I'm not sure I would hold my breath for them to do this though.

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