Duplicate content is frowned upon nowadays by SEOs for a number of reasons but mainly because it is seen to negatively effect your SEO effects. This myth started due to what most people back in the early SEO times use to do, and that was keyword stuffing, with a single keyword being repeated hundreds if not thousands of times on a specific website and there were ways for this to go unnoticed to the visitors to a website, these included writing the term hundreds of times in different orders in a tags file or my personal favorite, which was putting the keywords the same colour as the background so the search engines could see them but not the users…. Sneaky!
Anyway those times are long behind us, luckily and now it is the time for relevancy and quality. I talked about quality over quantity in my first post for backlinking but this type of quality is in regards to users and not search engines. Duplicate content does not directly lose you rankings, but usually it does directly lose you visitors, as people may have read the information before, or it may just be poor quality as you haven’t checked through and edited it yourself. Which means from a user perspective “content is king” but from a search engine one, I disagree.
There is a good video on why the duplicate content myth is a myth and why 95% of the SEO world believe it to be true, so I included it below. Skip to about 1.20 and he gives a great definition there. Using a great example of Huffington Post.
As you hopefully just saw and listened that duplicate content is over exaggerated and it is not all that bad! Personally I would never recommend it because if you are trying to make a sale or create leads or whatever you need your own content as you can say it best not what someone else said on their website a few weeks ago. But it does not effective your SERPs negatively.