It would be nice if we can see a breakdown of P&L. I see the indie dev claims to have “over 7500+ businesses” as customers. But also a very generous free tier.

I see the post is getting eviscerated in the comment section. But if this person is spending mere cents in operating costs when compared to the profit earned each month or year (I think in business terms this is known as customer acquisition costs). Then I would say that is truly “frugal”