> unless you specifically ask for their name/number, which is awkward

How is this any less awkward? "Oh do you have the new Friendster app?" "Friendster? Isn't that from the 1900s?" "No, the new Friendster, see you download it, register, then we bump phones...."

Maybe just because I'm an autistic introvert, but the idea of asking someone to exchange numbers is terrifying enough, but at least this is an almost universal social ritual that people understand implicitly. I ask if you want to keep in touch and exchange phone numbers. I do not need to explain literally anything else and the other person almost always knows what I mean, how to do it, and what thin social relationship that implies. And if they don't seem to understand or are hesitant, but are otherwise coherent and cogent, I take the message that they don't want to keep in touch.

Now add a new app to download (iPhone only), a new social network to register, a new social ritual... Are they being hesitant because this is a new app or because they don't actually want to keep in touch? No thanks.