Seth Godin in his The problem with search engine optimization could not, in good faith, recommend an SEO.
"Because it's a black art, it's really hard to tell who's good and who's not. Andrew Goodman is good, there are people who are less reputable... no matter what, it's hard to guarantee you'll get your money's worth."
Cre8asiteForums discusses, in Seth Godin interrogates SEO
Is he right in his assessment of search engine optimization?