Rand Fishkin looks at three content classifications -- editorial, machine-built, and user-generated -- defining "unique content," for each, why it's important for Web sites, and how to generate it. Search engines can identify weak content by analyzing the structure of a Web page.
Finding something unique on a Web site can boost rankings in the SERPs. Some sites have an unfair advantage. For example, if a small news Web site posts an interesting article and CNN publishes it, the larger Web site will get the credit. The search engines are working on becoming more fare about giving credit where credit is due, even for small Web sites.