The problem is, there doesn't seem to be much elasticity in the size of the market. Books are rivalrous goods: an hour spent reading book A is an hour you can't spend reading book B, or watching a movie. And a lot of people prefer to watch movies -- or play computer games, or kick a ball around -- to reading books for recreation. Unless we can work out how to convince more people that reading for pleasure is fun then we're in danger of disappearing into a zero-sum or negative-sum game: it's a gradually dwindling recreation, in the very long term, simply because of the increasing number of competing recreational activities. (NB: This is not a bad thing per se, it's only bad in the context of declining book consumption.)

Put it another way: posit that there is a constant number X readers out there who want to buy the next Charlie Stross novel. Is it a better strategy for me to pursue sales at a higher price point, or lower? Now posit that I might acquire more readers by lowering my price point ... but is it a linear relationship? Will I get my hypothetical profits back by deep discounting?

Answers on the back of a postcard, please. (Bearing in mind that actually doing the experiment is highly dangerous, because that's an entire year's income stream you're jeopardizing if you get it wrong.)