1. Unrelated Keywords 2. Keyword Stacking and Keyword Stuffing 3. Tiny Text, Hidden Text, and Hidden Links 4. Cloaking 5. Doorway Pages or Gateway Pages 6. Bait-and-Switch or Page Swapping 7. Duplicate Content or Mirror Site 8. Spam Blogs or Splogs 9. Blog Spam or Comment Spam 10. Trackback Spam 11. Spam Ping or Sping or PIngback Spam 12. Referrer Spam 13. Link Farms 14. Cybersquatting or Domain Squatting 15. Typosquatting or URL Hijacking 16. Social Networking Spam 17. Cookie Stuffing or Cookie Dropping \ Conclusion This list covers the popular forms of black hat SEO, but all shady techniques should be avoided. If ethics alone aren't a deterrent: Performing black hat SEO can lead to a damaged reputation, getting websites banned from search engines, and even lawsuits for copyright infringement. There are plenty of ways to legitimately improve website visibility in the SERPs. It may take time for a Web page or website to become popular, but it's a process that has a better chance of surviving in the long-term. Remember that the goal is to provide a service to visitors. Once you do that, with white hat SEO, the rest will follow.