Dan Ariely mentions these types of products (albeit in the context of cheating): the more removed the product is from real money, the easier it becomes to justify all kinds of actions you normally wouldn't perform: stealing it, spending it, etc.
Yes, and once you've converted the money to Amazon Coins, you've mentally set it aside to spend (sort of like poker chips) and won't think about your purchases as much as you would with real money.
Yes, they do. But when they see the money in front of them, they think long and hard about it. When, however, you introduce all kinds of financial instruments, you are no longer seeing money rather some abstract thing, and THAT makes it easier to rationalize all kinds of actions.
