Outside of Big Search
It's important that you don't put all your "eggs in one basket" so to speak in anything that you do. When it comes to investing, best practice says that you should spread around your money into stocks, mutual funds, bonds, etc. and the same principle applies for marketing via search engines.
While there is no debating that Google (and mainly Google), Yahoo and MSN (maybe AOL) drive the vast majority of natural, organic traffic to websites, that does not mean that there aren't other search engines and portals that provide users with a fundamentally unique value proposition. Sure, these search engines are new, and in some cases in a seemingly perpetual beta but they're high tech and in some instances fascinating which is why a small segment of the Web population end up using them.
The Online Education Database has published a good list of the Top 25 Web 2.0 Search Engines that is definitely worth a look if you're interested in spreading some of the content wealth you've been building.Technorati Tags: yahoo, google, msn, aol, search engines, alternative search engines