When trying to figure out how to optimize their own site for search engines, some webmasters figure they should look at how the site for the search engine itself is built. That isn't a good idea. Search engines don't build their sites to be SEO friendly.
Search engines don't need to build their sites to be search engine friendly. Search engines get most of their users from branding and search box placements. They don't have to optimize their search engine to appear in other search engines.
Even for other sites owned by the search engine, SEO may not be important. Search engines often drive traffic to their other web properties through widgets at the top of the search results rather than by getting their other sites ranked well in the search engine.
Search engines don't always follow their own rules. A search engine may not punish one of its own sites for violating the search engine's own webmaster guidelines.
It is better to survey a wide variety of other sites when looking for SEO examples. SEO forums and other web communities also offer a wealth of knowledge and experience.
This article was written as part of a series about SEO myths.