There's a very interesting book called
Second Lives, by Tim Guest. In one chapter he tells how a couple of people made a (real) fortune exploiting a loophole they accidently discovered which allowed them to duplicate products at no cost. It was like the goose that laid the golden egg - they just kept making new products after they'd sold all their stock. Can't recall what the product was, but I think it was an item of furniture second lifers buy for their virtual homes.
