Trying to game the system – Some companies attempt to use techniques such as keyword stuffing or cloaking (showing different content or URLs to users than search engines crawlers) in an effort to gain higher rankings, which is a violation of Google’s Webmaster Guidelines and can lead to your site being banned from search results. Cloaking is actually very easy for search engines to detect and de-rank, and they do it all the time (especially with big brands). So if you’re caught attempting to cloak content, you may be able to recover over time, but you will also likely see negative consequences in the short term that could include: lower rankings; loss of trust among users; or even complete removal of your site from Google’s index.
SEO practices that are outdated – SEO best practices change frequently in response to updates in back end technologies that support search engine algorithms, not to mention the shifting criteria used by searchers themselves when looking for information online. That’s why many people consider SEO to be a moving target, and for good reason.
SEO practices that are overly aggressive – When attempting to dominate or manipulate Google rankings, it’s important to keep your head on straight and remember to practice white hat optimization techniques only. If you attempt to use black hat techniques to deceive Google in any way (for example, by creating link farms or hidden text), you will probably end up hurting yourself in the end because Google will de-rank your site and possibly even ban it from showing in search results at all. This can lead you into a downward spiral where lower rankings lead to less traffic leads which leads right back into low or non-existent rankings. What does this mean? You either need a complete overhaul in your SEO strategy, or you might be screwed.