My site finally has decent showings in Google, we are climbing in MSN, but Yahoo's index sucks... They pop by once a week and index one page. Google comes every day, and we are 95% + indexed with them. MSN stops by daily too, but they seem to have a hard time breaking the 25% mark for indexed pages, not sure why, but what can you do..

How have you become successful with Yahoo? Any ideas on what I should do?

wait patiently

I also have this problem. My pages are indexed in Yahoo though, the problem is just getting listed for competitive keywords. I am listed in Google and MSN, but Yahoo is bringing pathetic traffic. Do I need to list in their directory or something?

Do I need to list in their directory or something?

Nope.
Maybe Yahoo users aren't in your target market.

i have opposite problem. loads of yahoo slurp spiders can be on my site at any one time and are there almost continously. I rank well with two of my key phrases. But yahoo still brings in pretty crappy traffic. Im lucky if the same keywords get me in the top 100 places on google.