According to nielsen wire, average Kindle user earns Sprint $2/month. Given 12 cents/MB price this yeilds 16.6MB on average downloaded by Kindle user per month. This includes book purchases, periodicals, blogs and web-browsing. It’s hard to speculate as to how much each of these activities contributes to the total number… My guess would be that web-browsing and blogs are negligeble at this point. As to books vs. periodicals, I’d guess that average Kindle user subscribes to 1 periodical and the rest are book purchases.
Another thing to consider are software updates. In little over 3 months since Kindle 2 was released there were 3 software updates totaling 12 megabytes in size. Cost to Amazon – $1.44. This is 24% of $6 wireless charges for this time period. Each update contains several packages – one for each previous version of the software. This makes it possible for users to skip updates and jump from version 2.0 to 2.0.3 directly, but it also bloats future updates. If these numbers are right updates will become a serious problem for Amazon in the future. We’ll see…