This is brand interactivity of a higher order because it gives visitors a tangible payoff they want to share. The genuinely wacky, polished videos are being passed around in Europe faster than ... we'll refrain from any mad cow references. It's a rare marriage of clever animation, invisible engineering, interactivity and savvy branding. And the Fjallfill brand enjoyed a 23 percent sales hike two months into the campaign for its line of sour-milk products. Sour milk? Now that's branding through design, for sure.