When Google makes an algorithm change to its  search functions, they try to make it as black and white as possible.

Specifically pandas and penguins.

Google Panda and Google Penguin are the names of two major Google algorithm changes designed to improve search results for users. Google is reducing the frequency of lame, spammy content rising to the top of Google search.  Panda and Penguin are designed to reward relevant, interesting and helpful content, not a bag of SEO tricks.

Two big takeaways:

You’re far better off updating one website daily with exceptional content than updating several sites weekly, monthly or less. Recency and quality are the two most important factors for search engine ranking for Google.

With the important exception of brand name domains,  keyword-rich domains are no longer valued, and in fact, may be devalued by Google.  Over-optimization is a big no - no in the Panda/Penguin age.

After both Panda and Penguin, quality content is not just king: it’s emperor, czar, dictator and deity.  Great videos, images and articles that are linked to from other sites and shared on social media get you more highly ranked, so that’s where you need to invest. The only way to shortcut that process is to buy keyword advertising.

Learn more:

http://www.searchmarketingstandard.com/outdated-seo-tactics-that-will-get-you-penalized

http://www.searchenginejournal.com/keyword-rich-domain-names-their-seo-value-invincibility/44940/

And the nightmare-inducing:
http://www.searchenginejournal.com/six-months-with-panda-story-of-complacency-and-recovery/44774/