Why SEO is a bit like cooking
One of Brian Dean’s best guide (Anatomy of a Perfectly Optimized Page) includes how outbound links, such as links to the Wikipedia page from where a certain information was taken from, can prove to be benficial for SEO.
As many other tactics this can help, unless it will be abused. And that’s why SEO is a bit like cooking, even if you know all the ingredients, you still have to use them in the right amount.
To put a keyword in bold once at the beginning of an article or to put the keyword in bold every time it appears in an article can make the difference between a small boost in relevancy and a spam looking article.
So after learning what SEO is, make sure you’re not abusing the tactics and just.. get used to sprinkle some here and there.