I want to talk about what I now think is one of the core challenges for designing large-scale social software. Let me offer a definition of social software, because it's a term that's still fairly amorphous. My definition is fairly simple: It's software t
With the caveats that Alexa’s data is not comprehensive—and even if they had perfect stats, “Alexa Rank” is still just one definition of popularity (a combination of reach and pageviews)—here’s the 10 most popular social media sites (with corr