Forum Moderators: open
There used to be lots of ways to spam Yahoo, but since they've been featuring Google's results and hiding the Directory listings, there's no reason to spend much time on Yahoo.
If your site contains some unique content & is relatively well coded, you should be able to get listed (if you pay of course).
If you can get listed in categories that get served high in the SERP's, you could still get traffic through those listings.