Meet Ad Age's 2015 40 Under 40

This year's class of achievers have many varied accomplishments, but they all share one trait: They are smart forward-thinkers who will be driving the business for years to come.

#38 Luke Mansfield

Q. From what mistake did you learn the most?
A. I used to run a TV shopping channel in the U.K. The more I liked a product the less we'd sell. If I hated it, we'd sell out in 10 minutes. It taught me, "You are probably not your customer." I've embraced that and preached it to my teams ever since.