There was a time when Yahoo was the best search site around. They were quickly eclipsed by Google. Google is now facing pressure not from what we traditionally think of as search engines but from large sites that incorporate their own search engine.
In 2007 Facebook had over 600 million internal searches per month. According to Comscore and others Facebook has doubled in unique visits from this time in 2009. Facebook is clearly a primary destination for many. How are you taking advantage of people that are searching on Facebook?
YouTube, LinkedIn, Twitter and other social sites also have their own search engines. Yes, some of the content from these sites can be found in the major search engines but do you want to rely on them to expose your content? What if a visitor never goes to the search engine but rather uses the internal search engines?
In real estate the sales adage is: location, location, location. This can also be applied to search marketing. You must be found where people are searching. You can’t tell some where to search. All you can do is ensure they find you wherever they search.