Analyzing your competition should be the second step taken during the SEO process (right after and sometimes even during keyword selection). Looking at what and how your competition have positioned their website where you want yours to be placed will lend great insight into how to get yours there.

The above statement should not be taken as meaning that early in the campaign is the only time that competition analysis is important. Once you are holding a top position your competition will undoubtedly renew their efforts to take back what you have replaced. Competition analysis is a step that must be taken to find out what you need to do to take a top position but which also should be performed periodically to detect your competitor