Who is this fooling, people hoping, just maybe, Blizzard accidentally sent them a key for a game they didn't purchase? If you bought off Blizzard's website, you've probably already been playing for a week (and already activated your game). If you didn't buy off Blizzards website, you should realize that this isn't your receipt, and its probably bogus. Just like all those emails from girls who "saw your profile on facebook".
Stupid people should be banned from the internet.