Ranjith Kumaran 11.23.12 6:02 PM It's not what you say, it's what you do—and how quickly you do it. Ranjith Kumaran, founder of PunchTab, on how to handle negative feedback. Newsletter Get the latest Fast Company stories delivered to your inbox daily. Send I'd also like to receive special Fast Company offers ARE YOU REGISTERED TO VOTE? Register now to make sure you have a voice in the election.