Before Facebook acquired WhatsApp, the company was for a lot of its users, not a "must-have" service.
But delete it from your life, and you won't be much worse off.
The exception might be the businesses which rely on Facebook to advertise their wares.
Post-WhatsApp though, Facebook is much closer to becoming what we might call a fundamental service.
If WhatsApp disappeared from the world, it would have a negative impact on people's lives.
In a lengthy blog on Wednesday, Facebook CEO Mark Zuckerberg leaned into the idea of turning Facebook into a fundamental business.
That is, a business that would become essential to people's daily lives because it is practically, and not just emotionally, useful.