> I usually send an email every week or so linking the user to any new projects which have been posted. These emails are relatively short, however, they don't drive many clicks towards the site. Why is this? Over half of them open the email, but only 8% of the list actually clicks on the links.

Doesn't that just tell you that only 8% of the list were actually interested in viewing the new project? My guess is that if you made projects that interested more people then more people would click?