What I don't understand - part 1

Welcome to Uncle Farfel's Home for part 1 of what I don't get. Part 1: Why do NBA players 'dap' each other after free throws? Kwame Brown just airballed a free throw and Luke Walton and Sasha Vujanic walked over to give Kwame a pound. He missed the next one and badly, too. The pound didn't help. It's become commonplace for the pound to occur after that 1st free throw - we expect it, we don't think anything of it. Do you realize how much time you've spent watching daps? It's a pointless exercise, there's no reason for it, it needs to stop. Dap that.    - farfel