“Facebook and Twitter may have pushed things into overdrive, but the idea of using communication tools as a form of “co-presence” has been around for a while. The Japanese sociologist Mizuko Ito first noticed it with mobile phones: lovers who were working in different cities would send text messages back and forth all night — tiny updates like “enjoying a glass of wine now” or “watching TV while lying on the couch.” They were doing it partly because talking for hours on mobile phones isn’t very comfortable (or affordable). But they also discovered that the little Ping-Ponging messages felt even more intimate than a phone call.”