Six Flags (NYSE: SIX) operates 20 theme parks in the United States, Mexico, and Canada while licensing others around the world. The company's parks are thrill-ride based, and that has worked well for the business, which posted solid gains for the first half of 2018.In this Industry Focus discussion, Vincent Shen and Motley Fool contributor Daniel Kline look at how season passes previously drove the ticketing strategy for the company and how that's changing.