bw3ttt - 7:21 pm on Oct 21, 2008 (gmt 0)

There are countless sites on the web that are essentially 99.9% duplicate content from Shopping APIs and product databases. They do not get banned from the index, but are effectively supressed to no man's land.

Go to shopping.com and cut and paste a paragraph of text into the Google search box. You will see hundreds of sites in the index with the exact same paragraph.

By having duplicate content you haven't actually done anything wrong so you don't deserve to be banned, but you don't deserve to outrank the original source either. You'll be buried in 300th place because people don't want results 1-10 to be the same thing.

As for your site, I would robots.txt your duplicate content UNLESS you have significant original content to go along with your dupe content ON THE SAME PAGE. If you have someone else's article on your site you should write a summary or some general thoughts on the article and have readers add comments.

There is no ratio of original to duplicate content that will cause you to remain in the index. Duplicating content is gray hat and is considered a tolerable nuisance by G. They can afford the hard drive space.