If the existing staff is doing a great job listening to the Grateful Dead while staring at Dilbert posters, you might think about hunting for additional players on the Dilbert site. We're increasingly encountering recruiters who have mastered the small niches. They understand that they're purchasing eyeballs. They'd rather pay more per visitor for the right visitors than less for generic visitors. Measure your results by testing several.
Results can vary by industry, profession and phase of the moon.
Only you can tell where the right intersection is for the results that you need. It's easy to get confused by a title. They are ads. They need to be written like ads. They are called postings because advertising was a no-no in the early days of the web.