A very smart bit of maths by self-published travel author Andrew Hyde following the launch, sales and stats of his book. The short of it is, Amazon is his worst-paying market - he receives notably less per book from them than he does from Apple, Nook or PDF - because as well as their 30% cut their “delivery charge” (levied on all books, but at 18MB a pop his (before compression after that post; he got it down to 2MB and they take $0.60 instead) is bigger than novels by a very large margin) takes $2.58 of his $10 cover charge.

But the same file, at the same size, hosted on the same servers (Amazon’s S3 cloud, on which half the internet depends), “delivered” in much the same fashion via anything other than a Kindle app/bit of hardware - only some of which will be via ‘whispernet’ and the rest via regular wifi the same as the rest of us, would cost $0.01 per five downloads, a massive mark-up for almost exactly the same ‘delivery’.

Also worth reading: an update on his sales sources after that post went massive.