Rob Hewitt has posted an impressive analysis of social media for ASLA and related sites. As he (and the amazing graphics) explains, ASLA has a dense network that is very interconnected internally. As he points out, the graphs that were created allow "one can see just how different the various professional organizations and news sites are in terms of their numbers, their dispersal, how intensely they communicate, and their national and global reach." And you can clearly see a difference between ASLA, APA, and ArchRecord.