From Digital Trends:
No matter how users stumble into a freemium game, once they’re hooked, almost every title is an unending staircase. They’re designed so that each step up only leads to more options, and more opportunities to spend more money, and more time in the pursuit of the next goal. It’s an infinite climb that, for some players, can have more in common with addiction than entertainment.
When it comes to understanding freemium, the best advice may be the message that Matthew Broderick received back in the ‘80s when he tried to win the War Game against a machine: “The only way to win, is not to play!”