YellowHeart is trying to solve a problem that should be familiar to anyone who’s ever tried to buy a ticket for a popular concert: Those tickets will often get snatched up by scalpers, who then resell them at a much higher price. In fact, the startup’s CEO, Josh Katz, said he founded the company because he’s a music “megafan” himself, and he was “just tired of getting ripped off by scalpers.” At the same time, he said this isn’t just a problem for concertgoers.