The evangelists of social media don’t understand this distinction; they seem to believe that a Facebook friend is the same as a real friend and that signing up for a donor registry in Silicon Valley today is activism in the same sense as sitting at a segregated lunch counter in Greensboro in 1960. “Social networks are particularly effective at increasing motivation,” Aaker and Smith write. But that’s not true. Social networks are effective at increasing participation—by lessening the level of motivation that participation requires. […] In other words, Facebook activism succeeds not by motivating people to make a real sacrifice but by motivating them to do the things that people do when they are not motivated enough to make a real sacrifice. We are a long way from the lunch counters of Greensboro.