The difference between mailing lists and LiveJournal as media for fannish discussion can best be understood in terms of focus. With the exception of author-centered lists (often used only for the posting of fiction, with perhaps the occasional discussion), mailing lists were organized around a particular topic. That topic might be as broad as “all things relating to this show” or as narrow as “fans in this region who want to talk about this pairing,” and posts not on that topic were highly discouraged (note 2). Perhaps most crucially, with the exception of a few multifandom lists (including the early Virgule list and the Symposium offshoot, FCA-L, groups.yahoo.com/group/fca-l/), mailing lists tended to be focused tightly on specific fandoms. Different lists would often have members in common, but discussion bled from one list to another only rarely.
LiveJournal, in contrast, is made up of many interconnected spaces, most of which are focused on individual people. On any given fan’s LiveJournal, she herself is the topic, choosing what to discuss or not discuss. Even LiveJournal communities sometimes serve only as link repositories, taking a reader back to a poster’s individual journal. The impact of this shift has been profound, and in many ways it has served to take the focus off the source and put it on the fan, and in turn, on fandom.