Doorway pages are another way that websites can attempt manipulate search engines. Doorway pages are pages with very little useful information for human visitors. Many times a doorway page will contain hundreds of links, which tricks the search engine into improving the site's ranking based on popularity. Doorway pages are not designed for human visitors and are annoying to land on.
Cloaking pages, on the other hand, are pages that provide unique content for different users. For instance, a Web user with a U.S. IP address will see different content than a Web user with a Canadian IP address.
Cloaking pages can also provide different content to search engines than to users. Cloaking pages are bad because every user should be able to choose what content they wish to view. The search engine should be able to index the entire site, rather than indexing information that actual visitors will never see.
Other sites use JavaScript to deceive the search engines. Because spiders cannot read JavaScript, the spiders cannot view the links and codes contained in JavaScript applets. Some sites use JavaScript redirect pages to redirect traffic so that human visitors see different content than the search engine. Redirect pages often take visitors to pages that they didn't want to go to.
Doorway pages and cloaking are not as common as a few years ago. There are fewer instances of these practices as search engines began punishing these practices. What a surprise that cheating doesn't work so well in the virtual world either.
