How does duolingo earn money?
Everything on duolingo is free so how does it earn money??
A related question might be "does Duolingo earn money?" It's had quite a lot of venture capital invested in it - but whether it's anywhere close to making a profit seems to be a guarded secret. Whether it charges for silly features or has advertisements doesn't actually mean that it's making a profit.
It didn't make a profit for the first five years. They are trying a lot of different things right now to make sure Duolingo survives, so different a/b groups to test different monitezaton strategies. I am guessing that is why different people are being offered different rates for streak repair. They are testing which amount is most viable to ask. A company can't use venture capital forever. So, it makes sense that since their other strategies weren't enough to make a profit, they are branching out.
While I don't like seeing ads, I'm willing to. I like that Duolingo exists and I want it to keep existing. So, kudos to the monitezation team for their hard work. Duolingo won't survive without them and they get a lot of negativity sent their way but keep doing their best.