Reminds me a bit of a social network concept of mine from years back: "Karachter"

"Imagine a social network where you only need, in fact you are only allowed, one friend. Imaging a messaging service so personal, so patient, and yes, so damned meaningful, that it only transmits one single character, to your one friend, each day. "

http://randomfeelsgood.blogspot.com/2014/02/announcing-karac...