A recent article by Jennifer Kyrnin asked and answered the question "Is Duplicate Content Bad for SEO? (The Short Answer is Yes)". We've summarized key points below, but encourage you to read the source article about duplicating content and its effect on SEO (Search Engine Optimization).

When is Duplicate Content Bad?

• When the main purpose is to have your content display higher in search engines or you want to manipulate search results. (Your site may be viewed as spamming.)

When is Duplicate Content OK?

• When the search engine indexes multiple URLs separately, but all URLs point to the same page.
• When the duplicated content is created for platform- or function-specific versions of your site such as mobile or printer-friendly pages.

What Can You Do to Reduce Duplicate Content?

• Avoid posting duplicate content (obvious).
• Use permanent 301 redirects, which will tell search engine spiders to stop indexing the old page and replace it with the new one.
• Link to home pages the same way every time. For example, http://precisioncomputingarts.com/ rather than http://pcartsonline.com/fastwebdev/home.
• Use "noindex" on syndicated content (pages that you have duplicated from another source), which prevents the search engines from indexing the content on your site.
• Avoid repeating boilerplate content on your site. Instead, move it to another page and then link it as needed.
• Expand similar content pages (such as a travel site that has boilerplate content but just small amounts of unique information about multiple cities). Instead, provide more unique information on each page; or, combine the pages.
• Provide more unique product content rather than simply copy/pasting product details from the source, such as Amazon.com or a manufacturer's website.
• Use "rel=canonical" link relationships, which Google and some other search engines use to determine the preferred version of content.