I find it fascinating when there's still room for innovation in crowded seemingly done to death markets like running shoes. There's always a sub-niche to go after, in any sufficiently large market there will be power users that are totally willing to shell out $250 for a 4% improvement. Given that these shoes according to the article last for 200 miles that's a couple of marathons and couple months of training tops before having to be replaced. Reminds me of the Tinker Hatfield doc on the Abstract series on Netflix.