When KAABOO Del Mar debuted in 2015, its focus on ritzy amenities - gourmet food and drinks, concierge service, Mercedes-Benz car service, private cabanas, surfing lessons, massages, a Las Vegas-styled "day club," and a swimming pool overlooking one of the main stages - made it seem like a high-stakes gamble.
While the attrition rate for new music festivals can be high - including this year's...