Maybe not the best example. Whatsapp started out as a paid service (even if it was comparably cheap, somewhere around a dollar per year comes to mind), but that didn't help them. They have followed the same trajectory as everyone else.

No one exists in isolation, if the market values your user base at ten billion then that is what it is. That also indirectly means someone with deep pockets could spend that order of magnitude of resources to compete with you. No one really wants to know how customer acquisition or sausages are made.

The best counter example is perhaps wikipedia. But they exist in a very special niche. Lots of people have tried foundations in other places only to be outspent by a loss leader.