Of course, even with academic conferences, where people are expecting to sit through lecture style presentations, feedback often indicates that the value is in the networking that comes out of the conference, not necessarily seeing the ideas/papers presented. (Which makes sense since if you really cared about the ideas, you could just read the journals or relevant blogs.) People don't go to conferences to pick up skills - they go to broaden their horizons, and make some connections. Even with prevention or national service conferences, you're going to see what the people on the cutting edge are doing, not necessarily to learn how to do what they're doing.