Astro-Turfing
Don’t launch a fake PR campaign or create a social networking upheaval based on false information just to generate traffic to your website.

Celebrity Look-A-Likes
When someone posts blogs, or creates blogs and forums under the name of someone significant. By “significant” I mean either a celebrity or someone who is well recognized in their industry. This celebrity impersonator will usually post comments or blogs that are damaging to a competitor. A less illegal, but certainly just as immoral act would be if an industry guru posted discouraging comments on their competitor’s site anonymously to ultimately drive traffic back to their own website.

Cloaking
Another form of misrepresentation. It’s when you are Showing one set of keywords and content to spiders and bots and a separate set of content to visitors.

Code Swapping
Other wise known as the “old switcharoo.” This is when companies take a top ranking page URL (usually one they’ve purchased) and swap it around so that it shows a different page that benefits their business. This is almost always a temporary fix, so it doesn’t make much sense to swap code if you don’t need to. Most companies have legitimate reasons to swap around their code if they are changing their business model or even owners. However, swapping code for the purposes of duping search engines is against the rules.

Doorway Site
Similar to gateway sites, but instead of having a link or redirection tool that the user follows, the user actually never even sees the doorway site. It’s just a fake page used to trick spiders into indexing the main page higher up on the SE.

Gateway Site
These can be identified as web pages with practically no content in them except for some (possibly hidden) keywords. They usually have some sort of text in the center or up top that says: “Click here to enter” They have no use to the web surfer, and their purpose is to simply rank high in SE results so that people can click on that link and be taken to the real website, which may not rank as well or have scammy content.

Google Bombs
Remember when you learned that if you Googled “miserable failure” George Bush’s website would pop up at the top of the SE list? That happened because hundreds (thousands?) of people linked Dubbya’s Whitehouse homepage to their websites by hyperlinking the words “miserable failure”. That was just a collective joke, but when one person Google bombs it can get them penalized or even banned – and that’s not funny. A website owner can create a Google bomb by hyperlinking the same (usually irrelevant) text to the same URL on various other websites. This will allow them to jump up in ratings when people Google that keyword. That is, until they get banned.

Google Bowling
Google bowling is essentially sabotage. It’s when a company links SEO spam links to a competing company’s website in hopes that Google will penalize or banish their competitor.

Invisible text
Not commonly used anymore since it’s easy to get caught. It’s when irrelevant keywords and phrases are hidden on a webpage by either making them incredibly small, hiding them in the html code of the page, or making them the same color as the page’s background.

Keyword and Meta Tag Stuffing
When companies fill up their web page with as many keywords and meta tags as possible in a pathetic attempt to get better SE Ratings it’s called stuffing. Typically they are hidden, but many times they aren’t. Fortunately Google doesn’t view this as “quality content” and it won’t work.

Mirror Sites and Purchasing Expired Domain Names
Sure, those expired sites may have great page rankings, but by using multiple websites and using them as mirror sites, (or websites with the same content, but different URLs) and to create backlinks to your original site, you’re making yourself a likely candidate for dismissal and penalties.

Page Hijacking
This involves creating a duplicate site of an existing website which will ultimately redirect users to an unrelated website. This specific tactic is often used to download malware and spyware on to users’ computers once they have reached the hijackers website. Whether or not the real website is malicious, this tactic will still get you banned.

Scraper Sites
Otherwise known as “Made for Adsense” (MFA) sites. These websites use automated programs that steal and amalgamate various content from top ranking websites in order to create original looking content for themselves or a third party.

Spam of All Kinds
There’s a few kinds of spam that we’re talking about here. Most of these are blantently unethical, like comment spam or spam pages, but others like “wiki spam” were used commonly simply because the marketer didn’t know better.

Blog Spam (Splogs) are essentially “link farms” (a colony of web pages that all reference each other) and are created for the sole purpose of spamming other blogs and driving traffic to either their own website or another “main” website that the spammer owns. They can do this by placing links, keywords and hyperlinked text on random blog sites. It is often a source of comment spam.

Comment Spam is when a company posts comments in the blog, forum, wiki page, guestbook or articles section of a high-ranking website in order to improve their own standings on a search engine. They are usually obvious to anyone to sees them. They may or may not be relevant to the discussion, they usually contain some kind of link or information that leads the reader back to the spammer’s website, and they are chock full of keywords making it even more conspicuous.

Spamdexing or Referrer Log Spam. This works on the basis that when a web surfer accesses one website through a link on another website, the website that originally “referred” the link is entered into a referrer log. This is essentially a list of websites that have referred people to that site and is usually displayed publicly on a special “links” page. Sometimes the referrer will employ the use of software to automatically and arbitrarily access a large amount of websites over and over again creating numerous amount of backlinks through these referrer index logs thus improving their page rank.

Wiki Spam. Wikipedia started using “nofollow” values in their html code back in 2005 because of this black hat tactic. It’s when website owners/managers use the open edit capabilities of wiki pages in order to backlink to their own website. While users can still follow these links, they will not affect the website’s rank on Google since Google’s algorithm is designed to ignore “nofollow” links.

Final Word on Black Hat SEO
About a year ago some major companies were caught using interns to do some Astroturfing. (I remember one company was Amazon’s Shelfari. I know there were some others but I can’t find a record of them anywhere.) They hired on interns, told the interns to post spammy blogs on other people’s sites and when they were caught, the companies basically told everyone that they knew nothing about it and blamed everything on the interns. Although these companies recovered in the Google rankings fairly quickly, their reputation with customers and blog owners remained bruised for a lot longer.

The general rule of thumb is to be careful and do your research. If you’re trying a new SEO method or your not sure about something ask someone who probably does know. Hiring a professional SEO/SEM company is always a good idea – just make sure they have a “No Black Hat” policy. If you do find yourself banned or penalized by a search engine, don’t panic. Banishment isn’t necessarily final and neither is falling in rank. Contact the search engine and find out why then work with them to correct the problem. You’ll usually find that they’re pretty reasonable. They know that most SEO/M managers don’t do these things on purpose and don’t want to be tagged as a Spammer or Black Hatter. Unless of course, they were going to change careers anyway.