This is a nice example of separating the wheat from the chaff.

The situation gets more complicated when there are t-shirts involved though.  When more people tend to hang around just because of the swag, the result is a distracted and impatient crowd which is not really interested in what you are talking about.

Tip: Give away the t-shirts in the beginning itself.  It is really not worth trying to keep uninterested people around through the t-shirts carrot.  The interested participants will thank you for it, and you might conclude the session with a recruit or two.

Ultimately, this is not about recruiting editors, it is not about writing grand reports, it is about identifying like-minded individuals who are genuinely interested in our projects - it is about making friends. :-)