Considering that their cheapest pricing is $12 (per month, 1 month minimum) and they claim 550 million users, either they made tons of riches or the numbers are to be questioned. I leave it to you to estimate which is more likely.
Doubt worshipping finds ways to not find a way to make something happen. Just because one person can’t see it doesn’t mean it’s not possible.
Is this your first time encountering a freemium business model?
I don't think that means paid users.
They also have a paid API.