http://www.foxnews.com/scitech/2011/...ntcmp=obinsite
Turns out iPad sales skew male and ereader sales skew female. Not everwhelmingly but enough to make financial impact, especially when install bases are factored in.
For example, as noted elsewhere, and above, womens magazines on Nook outsell their iPad editions, even though iPad outsells Nook about 10:1. This means, of course, that typical Nook owners are 10 times more likely to buy those mags than the typical iPad owner. They don't address "men's" magazines, like Maxim and the like though. (Does Apple even allow those mags into their corral?)
Lots of things go into those numbers, of course, but they do suggest that magazine publishers, in particular, need to recalibrate and diversify their digital strategies.
(And genre ebook publishers, too, but the smart ones already knew where their bread is buttered.)