Why is it mandatory to have unique content?

[stephen186]

One of the first SEO rules tells us to post just unique content.
I heard that the search engines are "punishing" the ones with copied content.
So, i was just curious, why is this fact mandatory?

[Jordan]

Because Google will drop you out of their database (and maybe ban you) if they find you are a "scraper" (copying content). You'll also have a harder time selling the site if you ever choose to do so.

[Josh-A]

Google ranks any website as per its SEO structure and SEO is all about unique content and links. If you wish to have your webpage indexed in google and people should link back to your website pages then all you need is fresh and unique content first.

[robertflorish]

Because Search Engines will punish the site for having the duplicate content and it has less impact.