Mathieu, I think you hit on the very problem of knowledge management itself! Everything from “why should I add that?” to “If I tell you everything, you no longer need me here.”

Perhaps networking such as this is intended to do just what we are doing–engaging in conversation, Tweets, LinkedIn, etc., and if I post something I am looking for (and vice-versa) and you see it, there is already a basic relationship so there is more likelihood for some reciprocity?