Remember, the idea of arbitrage is predicated on the principle that a selected good has a higher value in a single place than it does in one other. That may mean it sells for extra in California than it does in New York. But it might also imply that it sells for extra on-line than it does in a brick-and-mortar retailer. Winning at arbitrage means knowing how to determine which gadgets to purchase and which ones to walk away from. The goal — and the vital thing to making retail arbitrage work — is having an information advantage.