Lets list them 1. Most popular sites do not have any keywords in their name - Google (no search engine keyword). facebook (no social network keyword), youtube (no video steaming keyword) and many more 2. Google sells links all over it but will penalize your site, if it finds link selling being done (not sure if this is a fact but its definitely is a popular opinion) 3. SEO is basically about getting your website ranked on first page of search engine for the right keywords) but as per Google's official site, they is no definite way for it, which means the very concept of SEO is contradictory Pls add to list Cheers!
-As an Adsense user, Google will penalize you for having ads above the fold but any search in Google where money can be made is nothing but Google ads above the fold. -Google will penalize you if you scrape content to rank but doesn't have a problem when they scrape everyone else's work to use in their shopping results that they can monetize with Adsense.
Haha I completely agree with this one, although I believe most people have their own spin on how the feel SEO should be done, there is no one right answer i guess...