Does Wikipedia content harm the site / sites SEO ranking?
Wikipedia allows you to play its content.
If you want to use Wikipedia content in your own books / articles / websites or other publications, you can do so - but only in accordance with the GFDL. See here.
I am considering using some content on wikipedia to post pages on my site. For example, just taking the first couple of paragraphs. The motivation for this is not for SEO, but for providing information to the website user.
My question is: will I do this, will I harm my page? I have googled around and mentions of Google's Supplemental Index keeps growing.
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Having duplicate content within a site will certainly lead to your ranking being penalized, but probably not between sites. Google's algorithm is very advanced, so it might catch you. That said, if you need to host your site with content from elsewhere, it might be a sign that something else isn't quite right. Why not just link to the Wikipedia article? This way you will definitely not be punished.
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Google is a tricky beast, so there is always a chance of getting caught.
However, if you're planning on using a paragraph or two from Wikipedia, I can't figure out why Google doesn't mind as long as you have to provide a link to link to the article.
Another option is to rewrite the information yourself and then link it to Wikipedia to link to that information. This is a technique that I often use for technical pages as I get credit from Google for content and Wikipedia links both Google and the user correctly (using the Harvard link system).
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