Arbitrage is the financial term for buying an item in one market or venue and offering it in another market or venue, so as to take advantage of price differences between the markets. Applied to books, someone might buy a book on one site to sell on another, thus taking advantage of pricing differences. This can produce greater profit, after all costs, than use of a sole marketplace. Sellers can exploit buyers' ingrained habit of making nearly all purchases using one online venue rather than looking at the universe of offerings. Price differentials between markets have reinforced the practice termed bookjacking. See bookjacking / bookjacker. Sites like viaLibri.net search multiple bookselling sites and allow one to see pricing differentials between sites.