John sold 166 ebooks based on the invoice. When both electronic and physical media were available, the electronic sales were only 10% of the physical sales. I wonder if that is a typical breakdown for programming books? Had he avoided publishing in the traditional manner, do you think his net would have been better? I prefer atoms when reading on programming subjects particularly those that serve as a reference. It appears others might as well. Traditional publishing models do appear to limit the authors fair share of income but not having atoms available could be more limiting to your reward.