I felt that this video clarification from Google lead spam engineer Matt Cutts was a worthy review. Make sure to read my comments underneath the video.
You can view this video at YouTube at http://youtu.be/mQZY7EmjbMA.
The key take away on this video is that Google is grouping duplicate content by their algorithm and is only showing the top result.
So who exactly does this impact? Thousands of e-commerce sites that all share the same product descriptions and previously were able to compete with each other. Now that landscape has changed, and changed significantly.
Here’s my own quote found on the video page:
“So, I think I understand then that this leaves e-commerce stores that have the same exact boiler plate content as 20 to 100+ other sites sitting squarely in the duplicate content category meaning that Google is grouping the product pages across the web and only showing one in the search results due to relevancy. I would bet that the one that shows is the one with the highest CTR or most social shares. Since last year the algorithm changes that Google has made have significantly changed how e-commerce stores (that do not have unique products or unique content) operate; forcing most into AdWords to get site traffic.”