This is interesting (via PV): Netflix looks at piracy sites to figure out what shows are popular and worth carrying.

Yeah, I love it--I've never BitTorrented anything because it's a hassle. Not shockingly, I subscribe to Netflix. As with Amazon and iTunes, the main value of Netflix is convenience, and I'm happy to pay for that. It's not like BitTorrent doesn't have costs--costs in your time, costs in risks to your computer. If people are downloading from there, they're motivated to get over that hump--they want the work.

And I can completely see doing something similar with books--do a couple of freebie short stories/novellas in different genres or series, and see what catches on before deciding which one to pursue.