Players soaring through the air, bouncing over a court made of trampolines and competing to score points by jumping through a spinning hoop six feet off the ground: That was Rick Platt’s vision for SkyZone, a new sport he helped found in 2004. Jeff Platt in a Sky Zone trampoline park in Plymouth, Minnesota. Photographer: Patrick B. McCutchan via Bloomberg Though he built it, spending $2 million to recruit athletes and construct a 17,000-square-foot arena in Las Vegas, the crowds never came. SkyZone, as a sport, was a flop. But soon local skateboarders started banging on his door to play in the arena, so Platt bought a cash box and began charging $8 a head. Six months and 10,000 jumpers later, he realized he might have a business after all. When his son, Jeff, opened a second indoor trampoline park in 2006 in St. Louis, where he was attending college, it was cash flow positive within six weeks.