[projektfu]

It's all false advertising. Rosetta Stone was the pinnacle of false language program advertising, but the rest just take their cue from that.

A part of what I was saying, which didn't come across, is that I think Duo lacks a way to get people to move on. Being "free", there is less incentive to give it up when it stops having a benefit. Eventually it becomes a daily accomplishment, like doing the Wordle, that doesn't really improve anyone. That doesn't make it bad, but it hinders progress at learning a language.