Boston: HBS Working Knowledge Online, September 2009.
"The biggest discovery: pictures. "People just love to look at pictures," says Piskorski. "That's the killer app of all online social networks. Seventy percent of all actions are related to viewing pictures or viewing other people's profiles."
Why the popularity of photos? Piskorski hypothesizes that people who post pictures of themselves can show they are having fun and are popular without having to boast.
Another draw of photos (and of SN sites in general) is that they enable a form of voyeurism. In real life there is a strong norm against prying into other people's lives. But online enables "a very delicate way for me to pry into your life without really prying," the researcher says. "Harvard undergrads do it all the time. They know all about each other before they meet face to face. 'Oh, you're that guy that did that internship in D.C. last summer.' "
Piskorski has also found deep gender differences in the use of sites. The biggest usage categories are men looking at women they don't know, followed by men looking at women they do know. Women look at other women they know. Overall, women receive two-thirds of all page views."