I encountered this question What experts do we want to attract, and how? while browsing the meta. And though I don't know how to attract experts, I have an idea how to attract people asking questions - which, apparently, is the main problem of this site.
The idea is simple: see which questions have most hits from search engines and improve them - and their answers - so that whoever encounteres them has a better chance of staying on this site and becoming a part of the community.
Of course, if there are very little people finding our questions and answers that way, there is no point of spending time on the improvements. It's up to the mods (I think) to watch the statistics and decide.
I know it's a long shot. What do you think about the idea?