Welcome To Content Marketing
Many "new to content marketing" are blasting content out on new WordPress blogs, creating categories and loving life. Glad to have you and if you are reading this post then you know it is time to learn some "inside baseball" content marketing and SEO tips.
Google doesn't like content to be duplicated. Problem is we bloggers and merchants MUST duplicate content since some of our readers care about SEO while another set wants to learn about social media marketing.
An article like my Websites vs. Blogs post for Curatti.com (http://curatti.com/websites-vs-blogs/ ) could be categorized into web design, social media and Internet marketing. WordPress makes setting categories so easy the full ramification of that tag isn't fully understood.
If I categorized my Websites Vs. Blogs piece in more than one category it appears equally duplicated to Google. The fact I know the piece MAINLY belongs in Internet marketing is something I can share with Google by using a canonical URL.
I think of the canonical URL as the MASTERBLASTER URL, the URL I WANT Google to think of this content in. Other categories, any category NOT deemed the single MASTERBLASTER category, aren't "indexed" by Google's spider for that piece of content.
Google sees your intent and understands your instructions to mean "don't index the same content twice" and that makes Google's spider get all warm, fuzzy and happy. You just saved Google TIME and time in the Google algorithm is truly MONEY so chances for your website to gain in authority just went UP.
Chances to gain in authority when you have the same content in many categories goes DOWN. Your duplication costs Google money and time because they have to sort out if you are good and true or a spammer. Oh, btw Google NEVER sorts out if you are a spammer or good and true (and I wrote that sentence to make my SEO friends laugh :).
Google ASSUMES you are spamming and treats your dupe content with disrespect and annoyance. Should you create many categories and place content in them? Sure, but when you do so be sure to use canonicalization to send the right signals to Google and so they don't assume you are spamming.
Promise to write my next Curatti.com post on canonicalization and other important "SEO Ideas For New To Content Marketing". Marty
BTW, geat @Tomewer post with one of the most clear and concise explanations of a difficult topic I've read. Well done Tom!