It stands to reason that the ranking algorithms of each search engine may change over time, thus making necessary the need to make sure you are still high in the rankings.
..this is one of the things to consider when you decide to either outsoure or do "SEO" in-house according to this:
http://www.clickz.com/article/cz.3339.html
Of course, that article was written by the CEO of Web-Ignite Corporation, a search engine optimization (SEO) and positioning company. Hmmmm..well to me, there's an obvious bias toward outsourcing in the article that he wrote. IMHO, this article is nothing more than a sales pitch, posing as advice.
.....
So I read this article about "doorways/gateways":
http://www.rankwrite.com/gatewaymyth.htm
Essentially they say:
"If your site has content that naturally uses your relevant keyword phrases, and you follow simple guidelines on how to create your titles and meta tags, your Web site will rank high."
And this doens't seem to be anything noew..it seems to boil down to this:
*clearly state what the content is about
...so i still feel unsatisfied as to realizing what value and what real impact SEO consultants do or if it's just a self-aggrandizing term for "I-know-how-to-use-a-search-engine submission-form,-pick-key-words,-and position-them-at-the-top-of-the-page".