Here are a couple of factors that Yahoo/Bing consider far far more than Google:
1. Are you using an EMD?
2. How many links do you have matching the anchor text of the keyword you are trying to rank for?
For Yahoo/Bing you can register/buy an EMD, send 100k xrumer all with 2-3 anchors (and having most of it be your money keyword), do something similar with a low quality blog comment list and you can get some pretty good and stable rankings off of that alone.
I would of course still recommend going after some higher quality links (2.0s, blog networks, etc.) The good thing though is that Yahoo/Bing never punish you for links so you can go overboard.
They also have a very very sizable EMD bonus.
With all that being said, no matter what you do, it will take you longer to rank in Yahoo/Bing simply because they crawl links slower. So don't be discouraged if it takes you 45 days to rank in Yahoo/Bing when it would usually take you a couple weeks to do the same thing in Google. Your rankings will almost definitely come, and the great thing is once they come you really don't have to worry about then getting slapped or deindexed.