And yet you still see hairy key word formulas out there for "promised 500,000 hits per day!" Exactly the same holds true with search engines.
Covering is beyond the scope of the chapter. In the meantime here's a website with great info, although I will summarize the essential points for you:
Performancing
This post is an excellent introduction to the subject. Performancing is an established, credible specialist website.
Sadly, there's so much misinformation in this area that I need to waste half a chapter before I will let you know how to proceed debunking all the mythology out there. So, let us get down to the business section: