I think the fundamentals of search optimisation are essentially the same on most of the search engines. So although most of the data I use to build my keywords is derived from Google – I expect the same search patterns to exist on Bing and Yahoo. Of course, one could definitely extend the research and probably find some very valuable niche terms on the other search engines, but personally having looked at the volume of traffic Bing and Yahoo send to most of our sites, I don’t know if its worth the effort. For example, we have a well ranked site on all major search engines, but Yahoo and Bing collectively only send me 4% of my organic search traffic.

Have you had a different experience? Would love to hear your ideas on this.