Both Harry Potter and social networks are wildly popular at the moment, but the Potter series is at once finite and immortal. Finite in that there is no new content coming and immortal because books and film live on forever, especially when there’s a cult audience. The same can be said of music — Rick Astley may not be putting out any new singles, but we’re still being Rickrolled all these years later. Twitter and Facebook aren’t finite or immortal, they are evolutionary; they will shape-shift in how they are used by different (read: larger) communities, but will be where we get our information.