While there are many methods out there for building a successful web site, by far the most cost effective, over time, has proven repeatedly to be search engine optimization. The major advantage search engine optimization has over other methods of producing results online is that once good rankings are achieved, and provided the tactics used were ethical, you can essentially hold and capture targeted traffic indefinitely. Your web site may rise and fall in the rankings as a result of algorithm changes (the way a search engine ranks a site) within the search engines, but a solid and complete optimization of your site will ensure it will not disappear.