Citat:
1. Keyword/phrase over usage. Known by seo experts as keyword stuffing. This is also the most commong form of over optimization and also the easiest to recover from. When you are trying to rank for a specific phrase, you want google to find that term. Many webmasters will do this by placing the same term in the page title, url's, meta tags, body text, anchor text, header tags etc etc. It is important NOT to do this. Google will know what the subject of your site is without having to repeat the same phrase over and over. That just gives a poor user experience. Not only that, google will know you're trying to game the system. You could possibly overcome this by strong content and a good backlink profile, but it will likely still hold you back in some way or another.
2. Redirects. I seen a major competitor just lose its number 1 position after holding it steady for 3 years. This site was not only number 1 for this industry, but its also one of the top 500 most popular websites in the USA. It is a huge huge brand and it has just dropped to position #7 after being #1 for 3 years. One thing I noticed about them is they redirect several domains to their main site and they have bought out competitors over the years and just redirected them to their main site. Be careful not to redirect too many sites to your main business, and if you do, make sure to follow recommended procedure as offered by google.
3. Same/similar anchor in back links. This is an oldy but a goody. The best backlink profile is a well rounded, diverse and natural looking profile that has links coming from many types of venues. If all of your links come from blogs, that looks pretty artificial, what are the odds that all of the sites linking to you all happen to be blogs? Top that off with if these blogs link to lots of other unrelated sites, it wont take google's algo too long to detect that. Aggressive reciprocal links can hurt you as well.
4. Same Niche same server - This one I truly believe in, or it could be me just being paranoid. I always believed that having 2 websites on the same server in the same or similar industries will cause 1 or both of them to be punished. For this reason, I leave no trail for google to connect any 2 of my sites together unless they are completely unrelated. I make sure to have different whois info, I never use GA, adsense or any other means for google to connect two similar sites. I have no concrete proof of this one, but its something I feel strongly about.
5. Doorway/thin affiliate - Is the main goal of your site to get people to another site? Then google may just decide to drop your site and favor the source site since that would provide a better user experience. Counter this by offering something truly unique.
6. Link schemes/cheap backlink packages - Quite simply, dont waste your time. This does more harm than good and even if you do get a good ranking fast, it will fade soon enough. Any back link package is truly ridiculous and you are playing with fire. If you see any package that is offering you more than 100 links for less than $10, you should stay far far away. it also goes unmentioned you should stay away from ANY back link building schemes that include gaining mass amounts of backlinks in a short period of time. Links are votes and should be earned.
Cateva idei.