I don't live in the US and fully understand WhatsApp's ubiquity. As others have commented, AOL instant messenger once seemed "too big to fail". There's not th

I don't live in the US and fully understand WhatsApp's ubiquity. As others have commented, AOL instant messenger once seemed "too big to fail". There's not that much friction in changing to (or simply adopting a second) chat app - especially one which uses your phone number as an identifier.