Search engine spammers never prosper. Sooner or later, they get caught. And when they do, it's almost never pretty.
Consequences can include ranking penalties, removal of the site's "voting" power (i.e., ability to pass PageRank), incomplete indexation (i.e., a partial site ban), or, worst of all, getting "graybarred" (i.e., a total site ban, when the PageRank meter in the Google Toolbar is grayed out).
You can't exactly just pick up the phone and give Sergey or Larry a call with a "Mea Culpa" and then everything magically comes right again. It could take years for a business to recover from a site ban.
Not even the largest corporations spending big dollars on Google AdWords are immune. For example, BMW recently had its entire BMW.de site banned from Google for a period of time because it created "doorway pages"—pages full of keyword-rich copy created solely for the search engine spiders and never for human viewing. To add insult to injury, BMW was publicly outed by Google engineer Matt Cutts on his blog. He made an example of BMW, and all of the SEO community became aware of the carmaker's indiscretions.
Search engines rely primarily on automated means for detecting spam, with some auxiliary assistance from paid evaluators, spam vigilantes, and even your competitors. Within the bowels of the Googleplex and the Yahoo, MSN, and Ask HQs, PhDs write sophisticated algorithms to look for abnormalities in inbound and outbound linking, in sentence structure, in HTML coding, and so on.
That effort is augmented manually, by users submitting spam reports (such as the form at www.google.com/contact/spamreport.html), and by human reviewers conducting quality reviews. In fact, last year a confidential Google document called the "Spam Recognition Guide for Raters" was leaked to the public (and it's still available at www.searchbistro.com/spamguide.doc). The guide delineates some of the criteria for recognizing search engine spam, such as whether the site is a "thin affiliate."
"Black hat" search engine optimizers can be very sophisticated in their ways, and they operate under the principle of the ends' justifying the means. They are prepared to get caught, and when they do they pick up and move, setting up shop elsewhere. Or, more typically, they have thousands of other sites to fall back on. But you can't operate your business like that, nor can you afford to unwittingly employ an SEO agency that uses unscrupulous black hat tactics in order to reap short-term gains.
Are you confident that the tactics you, your web designer, and your SEO all employ won't get you slapped by the search engines? If you can't say with absolutely certainty that you're squeaky clean, then you'd better study the following list of black hat tactics to avoid:
- "Sneaky redirects"—redirecting visitors immediately as they enter your site from a search engine
- Hidden or tiny text—making the text the same color as the background; or shrinking the font size way down; or employing noscript, noframes, iframes, or hidden <div> tags to hide text and/or links
- Keyword stuffing—the excessive placement of keywords within web pages (e.g., in alt tags, meta tags, etc.)
- Targeting irrelevant keywords—optimizing for popular keywords that have no relevance to your business
- Selling PageRank—selling text links to advertisers/partners in order to pass on PageRank to their sites
- Trademark infringement—mentioning competitor names in your meta tags and elsewhere
- Duplicating content—making numerous copies of web pages or excerpts of web pages
- Spamglish—nonsensical, keyword-rich gibberish
- Doorway pages—those that aren't useful or interesting to human visitors
- Machine-generating pages—using software to create so-called content for search engines
- Pagejacking—hijacking or stealing content from high-ranking websites and placing that content on your site with few or no changes
- Cloaking—detecting search engine spiders when they visit and modifying the page content specifically for the spiders in order to improve rankings
- Participating in "link farms"—linking to, or receiving links from, "Free For All" sites or link networks, which typically contain many links per page and are poorly organized
- Buying expired domains with high PageRank—snapping up domain names when they expire with the hopes of laying claim to the previous site's inbound links
- Multiple domains without redirecting—in effect this is duplicating content
- "Thin affiliate"—ushering people to a number of affiliate programs without providing any added value
- Linking to "bad neighborhoods"—linking to link farms or otherwise unsavory sites
- Blog comment spamming—posting bogus comments to blogs, with links to your site
- Guestbook spamming—posting bogus comments to sites' guestbooks, with links to your site
- Splogging—creating blogs and posting to them content stolen from other sites
- Google-bowling—submitting your competitor to link farms etc. to get them penalized