My initial inclination in responding to this question is to flip it on its head. This means that rather than addressing how we build digital cohorts and academic communities in (presumed) online spaces, instead we might focus on how cohorts and communities are dependent upon and energized by ongoing collaborative labor based out of specific, physical spaces.
Before attempting to build digital cohorts in my role as Coordinating Editor for In Media Res, I found it crucial to build an academic community from the ground up out of a defined place: my office at Georgia State University. Prior to agreeing to take the site over from Avi in June 2010, it was crucial for me to know that I had a group of graduate students with whom I could collaborate on building an a set of protocols and collaborative practices for the site. We had to work closely – both online and via in-person meetings – to do everything from brainstorming theme week ideas to developing templates for communicating with curators to creating training sessions for new staff members. (That is just the tip of the iceberg regarding what more than a dozen of us have accomplished over the past several years.)
Fortunately, several people in my department saw IMR as an opportunity not only to network with scholars, journalists, critics, and the wider public about topics of interest to them, but also viewed the site as a way to forge more meaningful relationships with each other. Thus to me, as important as IMR has been to me in introducing me to the ideas of individuals with diverse research interests around the world, it has been equally important in helping me cultivate deeper interpersonal relationships with librarians, filmmakers, scholars, and graduate students at my own university. In short, my experiences working on IMR indicate how utopian visions of large-scale digital interaction are fueled by the pragmatic efforts of smaller communities rooted in specific spaces and places. Further, these efforts must consistently be nurtured and supported, both institutionally and socially.