So - the people who make enough to pay you a salary - what business are they in, and how do they make their money?

I'm not trying to be snarky. Well, maybe just a little, but in a good-natured way - I think you got a good deal that probably met or exceeded your expectations, which is commendable!

But you did not create a sustainable business. To do so with ads is not impossible, but since each user generally gives you way, way less revenue than with something where they pay for it, you really have to parsimonious with resources per user.