Apple's Eddy Cue reveals the logic behind charging $0.99 a song when the company launched iTunes Store in 2003, despite the fact that Apple would lose money at that price: "There were two keys to $0.99 that we really believed in, and people didn't see." "Number one is when the price is $0.99, and it's consistent, you never have to think about price." "The second thing was that people could never do that, because at $0.99, if you're charging a credit card, you would lose money. Because credit…