[richardknop]

Signing up with phone number doesn't work for lots of young people I suspect. We don't have phone numbers of friends anymore, for example I have no phone numbers of even my closest friends, we have been communicating via internet since we have been teenagers (started with ICQ, then moved to emails then FB then whatsapp, never really needed to share our phone numbers as we don't ever call anybody nor send SMS).

This might be just specific to very international people like me who travel and work in many different countries so our phone numbers change often and keeping track of that is almost impossible.

[hobarrera]

Huh, that's interesting.

I guess this also varies tremendously by region. WhatsApp completely dominates non-work communication in Argentina; we don't use SMS, nor phone calls, and FB is pretty much is second place.

AFAIK, in the US people actually use SMS a lot, and I'm sure it's a bit different everywhere else.

More on topic though; you can use Messenger without an FB account and still find people by username.

[Foivos]

How did you sign up in WhatsApp without a phone number? Also, when you want to exchange contacts in WhatsApp, what you do it to pass the phone number registered in the service.

It seems that you have phone number that is in some way associated with you.