Joy Mangano, founder of the company Ingenious Designs and inventor of the Miracle Mop and Huggable Hangers, reveals product features gradually, performing a home-ec version of the dance of the seven veils. Her hangers are unbreakable! They are ultrathin, so they take up less closet space! They keep a lock grip, so clothes don't fall off! As these lessons unfold, viewers have time to absorb one before being presented with the next -- the argument is like a wave, growing inexorably in power. "She makes a clear link between the feature and the benefit, and she piles them up," says Anita Elberse, a Harvard Business School marketing professor. "So if you are not convinced by the first benefit, then you are convinced by the second or by the third. At some point you think, Wow, this is really an unbeatable combination of things, and you go for the phone."