Avoid Search Engine Blacklisting
The best way to avoid being blacklisted by the search engines is to avoid using some questionable techniques that were once popular to gain high rankings. Even if your website is not blacklisted by using some of the techniques below, it may be penalized (buried in the rankings) so your traffic will suffer all the same. When a search engine blacklists a website it will throw your listing off their site and block your site from coming aboard again. This can be done by blocking the domain name, the IP address or both.
Here are a few techniques to avoid, so that your site will not be blacklisted:
Mirror websites are sites with identical content but different URL's. This was once a method used to gain high rankings in the search engines, but since search engines are smarter now, this will only get you penalized or blacklisted.
Doorway (gateway) Pages
Doorway pages are pages with little real content for your visitors that are optimized to rank highly within the search engines. These pages are designed so that visitors will move deeper into the website where the real content lies. Navigation to the doorway pages are usually hidden from the visitors (but not the SE robots) on the homepage.
Invisible Text and Graphics
Using invisible text (text the same or a very similar color to the background) was once used to spam a homepage and some inside pages with non-stop keywords and keyphrases. Also links to doorway pages and hidden site maps can be done with invisible text (or invisible graphics). Some designers will create a graphic link with a 1 pixel by 1 pixel raster image and link this to a hidden inner page such as a hidden site map.
Submitting Pages Too Often
Submitting the same pages to the search engines within a 24 hour period can get you penalized and may delay your website from being listed in the rankings. Some search engines believe that pages submitted sooner than every 30 days is too much. The 30 day rule is a good rule to follow when submitting to multiple search engines.
Using Irrelevant Keywords
Using irrelevant keywords in a website's metatags and / or body copy in order to achieve high rankings will most certainly backfire. Search engines now want to see parity between these two areas and if your site is thought to be spamming with irrelevant keywords, you site will be penalized or blacklisted.
Automated Submissions to the Major Search Engines
Using an automated service or software to submit your website to the search engines can be extremely counterproductive. Most of the major search engines and directories accept manual submissions but do not like to be spammed with the automated ones.
Cloaking is the practice of deceiving both the search engine and the visitor by serving up different pages for each. The visitor sees a nicely designed and formatted page and the search engine robot scans a page of highly optimized text. Any practice that is deceptive should be avoided and the downfall of cloaking is that, if caught, the website can be banned permanently.
Using a Cheap or Free Web Host
Using a cheap or free web host can hurt in the search engine rankings. Frequent downtime, pages taken down for exceeding the bandwidth deter robots from indexing your site. If a robot cannot access your site often enough, your site will be dropped from the search engines. Hosting is cheap, so if you are serious about your website get your own domain name and host not one like geocities.com/yoursite.
Sharing an IP Address
Sharing an IP Address even from a legitimate web host can get your site in trouble. If you have cleaned up your website from all of the techniques mentioned above and your website still does not get relisted by the search engines in a couple of months, check with your host to see if you are sharing an IP address with other sites. If so, you may consider moving your website to a new host who will give you your own IP address or at least one that is not shared with another company who has had their IP address (an yours) banned by the search engines.
FAST's Director of Business Development and Marketing, Stephen Baker, has stated that globally there are approximately 30 million crawl-able servers and approximately two-thirds have been banned by the FAST network for spamming. If these numbers are correct, your site may be blacklisted or penalize for "guilt by association."