I think in most cases it's fairly obvious. I moved to a country that mainly use Whatsapp, and you can't miss it. People will tell you that they "Whatsapp" you, they ask for your "Whatsapp", your bank advertises customer support on Whatsapp, your local barber has the Whatsapp logo on his door, your colleagues want to add you to their Whatsapp group, your landlord sends the bills on Whatsapp, ads in the metro have the Whatsapp logo…
That sounds awesome. In many of the places I’ve been I couldn’t read any of the signage, it’s often not even obvious where the word boundaries are, it just looks like squiggles to me. And the apps people tell you by word of mouth, I often had never heard of. I just decided to stick with email. Boring, perhaps old fashioned, but safe.
