You've mastered your third shot drop on the pickleball court, when along comes padel, another racket sport that's suddenly all the rage. While pickleball has dominated US headlines, padel is giving it a run for its money. Last year, startup Epic Padel raised $10m to build clubs across the country. Pro Padel League raised $15m from investors this year, and CNBC airs select matches. But rapid growth doesn't always guarantee success — Sweden and Chile expanded their padel facilities rapidly but recently saw mass closures.