Using SEO in constant interval
 

I have come to know from many of friends who are in the field of the SEO for a long time that SEO is a onetime effort. Once, the promotion is over it is all about sitting back and enjoying. Is it true? But from many source in the internet like online tutorials and e-books I learned that SEO is a ongoing process and to get a good result SEO in a regular interval is needed. Is it true? Please help me as I am very much confused due to these different views and conflicted guidelines. Please leave your comments.

I have realized from my close associates who are well aware about the field of search engine optimization that SEO is an ongoing process.