As in anything else it all depends if you want to get by or be mediocre. SEO is a very competitive profession. There are no board exams or industry qualification tests; however I feel that what makes or breaks an SEO consultant is how well he understands the fundamentals. Notice I did not say the BASICS!

The entire SEO market lingo is easy to understand when you have good experience in HTML and PHP as well as other programing languages. Many SEO consultants are sometimes ex-programmers whose jobs have been outsourced and need another career.

People keep wanting to believe that "someone" is going to give them this majic formula that is going to grant them instant SEO skills, problem is this changes too much to fly on majic formulas. Like most professions SEO has a steep learning curve of a combination of web mechanics and quite a bit of advertising/marketing saavy.

If you find a client that has a "straight html" website please let me know; ours have web applications that are written in a multitude of languages from .NET to ASP to Java CMSs to PHP.