I dont download anything over 3 G cos it costs!
Well, not invariably. I have a cheap data plan for my ipad for when wifi is not available and quite a lot of data (measured in gigabytes, but it does get slowed down after the first five) as well as unlimited voice on the phone. Anything I get from Amazon via 3g to my kindle I already paid for when I got the kindle. So I might as well use it, if I don't I won't be getting a discount.