Are you talking about the so called black hat SEO methods and procedures? Well, using them your head might indeed begin spinning because the outcomes on ranks and traffic shares of your site could be very bad and discouraging in all cases.
Search engines in general and Google in particular are nowadays fully aware of the tricks some people might be thinking of using for artificially improving their domains ranks on the net and so, by dropping their ranks, they would prove them they are mistaken.
I think that is what he is getting at. It is all simple if you follow the guidelines that google has put out there. I would not recommend doing anything shady, you may get away with it at first, but the penalty in the long run is not worth it. SEO is a marathon not a quick sprint.
Black Hat SEO is something that you don't need to know any more. It is the unethical way of SEO. It is a practice of SEO that is against the policy of search engine.
lack hat seo means to cheat search engines. It can give you excellent result but for temporary. When spider of search engines will catch you, your site will be banned. And it is also true that visitors will come to your site but you could not convert them in to your business.
Here are some of the methods that falls under black hat SEO: