In your life, you have at least one relative stranger whom you’ve grown close to. Maybe it’s a doorman. Maybe it’s the cashier at the local bodega. Maybe it’s the guy who works in the next cubicle over. So what if you only know their first name, and you’ve never had a conversation that exceeded 45 seconds? Over months of opened doors, midnight candy bars, and borrowed staplers, you’ve become quite familiar. You have a bond, a friendship, that can only be built over countless moments of tiny social friction. So why would things work any differently online?

via Facebook’s Secret To Building Friendships: Many Small Interactions | Co.Design.