Comment by wizzwizz4

> Duolingo is just one example that there is plenty of money to be had even with dubious claims and a product that doesn't actually work that well.

No, Duolingo is an example that proves that there is plenty of money in taking a flawed-but-useful education tool, and making it much worse in specific, habit-forming ways. I don't know that it proves anything about the profitability of providing learning: merely about the profitability of providing the perception of learning / a habit-forming activity that you can persuade yourself is a virtue.

Perhaps showing people metrics derived from the "proved it with data", after each session, to provide the perception of progress even when the learning task is frustrating? Looking into gym psychology, rather than (video) game psychology, might help. You'd want to try to encourage intrinsic motivation, rather than extrinsic motivation, but I'm not aware of any research on how to do that.