It is a truism that rapid changes in technology have altered methods and rates of communication in our connected society.  We email rather than write a letter, we skim RSS feeds rather than sit down and read the paper, we Kindle rather than crack a book, and all that content gets to us so much faster.  The services we use and online communities we are a part of also change more rapidly.  We use Google now, when ten years ago Yahoo! was the new big thing in search.  We connect via Facebook, and grimace when we come across an acquaintance that still uses Friendster. Why the turnover?

Eric Goldman, former general counsel at Epinions.com, is taking an empirical look at the attrition rate of top Epinions.com contributors.  What he finds is surprising: among members who went inactive are former “top  users” who still derived residual income from their past Epinions articles.  Even money couldn’t keep them on the site!  Obviously, this implicates more than the typical distinction between content creators, editors, and consumers in online communities. How do you keep a community relevant and engaging for a fickle bunch of web users?

The easy answer is to keep a positive cost/benefit ratio for membership in the community.   The hard part of that answer is coming up with all the factors that keep that ratio high.  Some services are more dependent on technology for a positive ratio (think quality of search results), some on social dynamics (think critical mass of users on an instant messaging platform), some on quality and quantity of content.   What factors do you consider when deciding to view, participate or contribute on a sustained basis? Which is it, Digg or Reddit?