Throughout this chapter, we have provided many examples of how spammers try to circumvent search engine guidelines to obtain high rankings for sites that may not deserve those rankings. Of course, the search engines do many things to fight link spam.
The major approach the search engines use is to design algorithms that can detect and act on link spam. There are a number of things they can look at algorithmically. Here are a representative few:
The search engines can scan for nearby text, such as “Advertisement,” “Sponsors,” “Our Partners,” and so on.
Sitewide linking is unnatural and should be a rare part of your link mix (purchased or not). The only exception to this is the interlinking of all the sites owned by your company, but this presumes that the search engine will understand that the same company (or parent company) owns all of your sites. In general, sitewide links are a serious flag, especially if you have a lot of different sites that do this for you, or if a large percentage of your links are sitewide.
Of course, link brokers are knowledgeable about the link-detection methods listed here, and they do their best to avoid detection with the links they sell. But they can still run into problems. For example, in 2008, Google took action against a long-time proponent of paid links, Internet Marketing Ninjas (formerly called We ...