The experiment described in TFA is pretty clearcut. She saturated the torrents with fakes, and more people bought authorized copies.
But another experiment would be more interesting. Cut the price of the ebook substantially, and look at aggregate sales. After all, the marginal cost of ebooks is ~$0. And downloading torrents is more hassle (and more risky) than buying from Amazon or whatever. Maybe there's a price point that would minimize piracy and maximize sales.