I see a lot of job ads on SO, I've searched through them as well. It seems, however, that the ads are very broad in their targeting.
What I would like to see is ads based on tags.
First, it should display ads with relevant tags in your favorites before ads without relevant tags.
Second, it should place more weight on tags that you've got answer points in, allowing things that you're interested in or good at to be first.
This will keep the interesting stuff towards the top and encourage good answers within the community. It will also make the job lister happier, as they'll be able to get their listing seen by relevant developers faster.