Teaching colleagues, especially those in "New Media" and the "Digital Humanities," might find the pattern below interesting. The image is the report for activity on an academic mailing list from 1999 to present. Similar patterns are visible when I check other mailing lists. It's like the USENET statistics. Where are people going to discuss academic topics?
I left the WPA-L and other lists, because they were too often off-topic and/or not about scholarship and pedagogy. I didn't enjoy the mailing lists anymore. The fun was gone, though a core set of users remained active on other issues. Maybe that's the problem for all online spaces: they become insular.
The loss of RSS from some sites also reduced my connection to academic discussion. I really miss having easy access to RSS, and don't like Twitter or Facebook as my news feeds.
From 2002 through 2010 was an active, exciting time for online communities. That's eight or nine years, which is a long time on the Internet. Still, the loss of these communities disappoints me.
I'm using my phone more than my computer, and I'm reading fewer sources with almost no "community" content. Slashdot and MacRumors are about the only communities left that I check daily.
Even the theater and film communities I used to love are on life support. They tried podcasts, but that's not community — it's top-down from the organizations, not the membership.