It always depends on your definition of "popular".

Are there users using it regularly? yes.

Thousand? Yes. Millions? No.

How many people do you want on your social network before you consider it popular enough to use?

Great thing about software like GNUSocial is that organizations can run their own social infrastructure, a bit like how organizations could previously run their own email or any other service infrastructure, rather than rely on a third-party company to dispatch it on your behalf.

By organizations, I'm talking about business, government agencies, educational institutions, et cetera.

> a bit like how organizations could previously run their own email [...] infrastructure

"Previously"?

Don't read too much into that, it was a poor choice of wording.