SearchDay - Optimizing Keywords for Search Engines - 11 June 2002
Effective optimization for search engines requires more than just fiddling with web pages -- you need to carefully select and focus your efforts on specific keywords for maximum success.

A search engine marketing strategy encompasses many elements including an understanding of your target audience, which search engines they are likely to use, and what keywords they might use to find your product or service.
http://searchenginewatch.com/searchday/02/sd0611-keywords.html