Webbots, Spiders, and Screen Scrapers - Michael Schrenk [108]
Well-Defined Links
Search engines generally associate the number of links to a web page with the web page's popularity and importance. In fact, getting other websites to link to your web page is probably the best way to improve your web page's search ranking. Regardless of where the links originate, it's always important to use descriptive hyper-references when making links. Without descriptive links, search engine spiders will know the linked URL, but they won't know the importance of the link. For example, the first link in Listing 26-1 is much more useful to search spiders than the second link.
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Listing 26-1: Descriptive and nondescriptive links
Google Bombs and Spam Indexing
Google bombing is an example of how search rankings are affected by the terms used to describe links. Google bombing (also known as spam indexing) is a technique where people conspire to create many links, with identical link descriptions, to a specific web page. As Google (or any other search engine) indexes these web pages, the link descriptions become associated with the targeted web page. As a result, when people enter the link descriptions as search terms, the targeted pages are highly ranked in the results. Google bombing is occasionally used for political purposes to place a targeted politician's website as the highest ranked result for a derogatory search term. For example, depending on the search engine you use, a search for the phrase miserable failure may return the official biography of George W. Bush as the top result. Similarly, a search for the word waffles may produce the official web page of Senator John Kerry. While Google has adapted its rankings to account for a few well-known instances of this gamesmanship, Google bombing is still possible, and it remains an unresolved challenge for all search engines.
Title Tags
The HTML title tag helps spiders identify the main topic of a web page. Each web page should have a unique title that describes the general purpose of the page, as shown in Listing 26-2.
Listing 26-2: Describing a web page with a title tag
Meta Tags
You can think of meta tags as extensions of the title tag. Like title tags, meta tags explain the main topic of the web page. However, unlike title tags, they allow for detailed descriptions of the content on the web page and the search terms people may use to find the page. For example, Listing 26-3 shows meta tags that may accompany the title tag used in the previous example.
Listing 26-3: Describing a web page in detail with meta tags
There are many misconceptions about meta tags. Many people insist on using every conceivable keyword that may apply to a web page, using the more, the better theory. In reality, you should limit your selection of keywords to the six or eight keywords that best describe the content of your web page. It's important to remember that the keywords represent potential search terms that people may use to find your web page. Moreover, for each additional keyword you use, your web page becomes less specific in the eyes of search engines. As you increase the number of keywords,