So it's finally official: Bing will provide organic search engine results for Yahoo while Yahoo will provide PPC ads for MSN's Bing. This is good news for three reasons: First ranking organically with Bing is easier than with Yahoo. Second, since Oveture has high conversion rates, this will allow you to increase your sales since it will also cover MSN's traffic. Finally, this will mean you won't get as much dependant from Google anymore as with Bing and Yahoo joining forces, you will get a new bigger source of easier traffic, which will be almost as important as Google's.
So I would suggest you start optimizing your site for Bing right away so that you take advanatge of both Bing and Yahoo's free traffic ...