Researchers from Stanford, Harvard and the London Business School conducted five studies that examined both hypothetical scenarios and actual regifting among friends. They found that gift recipients believed regifting was as bad as throwing the present in the garbage. Gift givers, on the other hand, were significantly more offended by trashing their presents. They’d be much happier if that gift were given to someone else.
Here's how you know regifting is rude: you get embarrassed when you get busted.
Regifting has become so socially acceptable, one of the Kardashians now has a guide on how to do it properly. (... Although, doesn't the Kardashian approval of regifting just underline its tackiness?)