WhatsApp’s original model was $1 a year. That would have been a reasonable fee even for most developing countries. Job posting sites make money from the poster and don’t have to be ad supported.
What would a $1 a year model do in terms of opening the market up to competition? That seems like the worst of both worlds, no additional competition, and we make these difficult for those without much money.
Were they profitable with that model?
They only had 30 employees when they were acquired. I'd say yes.