According to comScore Google sites led the U.S. core search market in November 2009 with 65.6 percent of the searches conducted, followed by Yahoo! Sites (17.5 percent), and Microsoft Sites (10.3 percent). Ask Network captured 3.8 percent of the search market, followed by AOL LLC with 2.8 percent. I myself have been heavily influenced by the Google search engine and have been studying why certain sites rank better than others. Google's algorithm is a very important factor we need to consider.

A note on inner-string relevance: String-parsing algorithms use logic similar to that which we use in our everyday lives. Human beings find it easier to remember the numbers at the beginning and end of a list, while the "filler" in between is less easily recalled. Similarly, a search engine algorithm will consider a keyword found at the beginning of a title, heading, or ALT text character string to be more important than one appearing in the middle. Exact matches are much more important than partial matches (where a two-word keyword phase is matched on one keyword but not the other).

What is Google's Algorithm?

 Now, let's try to understand what Google "sees" when it analyzes a web page. The percentages are only estimates -the real Google algorithm is much more complex, and is surely weighted much differently than what is crudely summarized in the following table.

Link popularity is the most highly touted of Google's algorithm features. Also known as PageRank, link popularity determines whether the rest of the Internet considers your website to be important.

Not all links are equal: a link from a popular index page is weighted far more heavily than is a link from a comparatively unpopular supporting document. Also, the makeup of the link itself is important. If other people already indexed within Google's database link to your website with a text link that includes your target keyword phrase, then chances are good that you will rank well for that keyword. Similarly, if using images for reciprocal link campaigns, make sure that the image file name and ALT text are optimized for your top keywords. That way, when people link to your site, you'll be able to make it really count.

In other words, you need to make sure that your incoming links use your keyword phrase in their link, ALT, and surrounding body text.

Title tags are of the utmost importance to any Internet marketer. It is often on the strength of the title alone that relevant results are considered. Be sure to include your top keyword phrase in the title tag, and make sure that the title appears before other, less important tags, such as the meta description or keywords. Don't be afraid to place an important keyword twice in the title in order to compete with other highly relevant websites. Sometimes this is all that is necessary to catapult in the rankings.

URL, and file names are attributes that are a serious nuisance to consider when marketing. Many webmasters have resorted to purchasing large quantities of keyword-specific domains as a means of maximizing each document's relevancy when considered by search engine algorithms.

Heading text is very important. If you want your web page to rank well for its keyword, the easiest thing to do is add a single < H1 > tag as the very top of your document. The first text that the surfer sees should be an < H1 > tag that begins with your keyword phrase. Lesser numbered tags (such as < H2 > ) are not considered to be as important as the < H1 >. Consider reusing your title or meta description here so as to avoide writing any unnecessary sales copy.

Body text is an important part of on-page keyword relevance. Make sure that your body text is sufficiently long (several paragraphs is ideal), and keeping the inner-string relevance mentioned at the beginning of this article in mind, try to make your paragraphs begin with the keyword phrase in question. Unlike Altavista, Infoseek, Inktomi, and Excite before it, Google is not super-critical of on-page keyword density. Repeating a single word over and over is unlikely to win many extra points. Just make sure that your keyword does in fact appear within your document's body text several times. It is the other attributes that will win top spots at Google.

Images are important too. Make sure that your site's logo contains your keyword phrase in both, its ALT text and image file name (keyword_phrase.jpg). Don't rely on 1 x 1 pixel images for links, either: Google downloads your images and performs analysis for its image search, so you can be sure that the old methods of jacking up link popularity at the non-defunct Excite and dying Altavista just won't cut it anymore. A 1 x 1 transparent image won't be considered relevant, and you will not receive credit for outgoing links utilizing this scheme.

 On-page link analysis refers to the links on your web page. Are the web pages that you're linking to themselves relevant? Do their URLs contain your keyword phrase? Does the content or ALT text surrounding the link contain your keyword phrase? Optimize these additional document attributes in order to fully exploit mosaic-patterned search engine algorithms.

 What's not important at Google may be analyzed by the other search engines, but these attributes will likely play a less important role in future search engine algorithms as competitors seek to emulate Google's relevancy. These increasingly worthless attributes include comments, text colored the same as its background, and the meta description and keywords tags (which Google does not analyze when ranking your site). Thanks to the addition of link popularity measurements and with the decreasing importance of on-page document relevancy, repetitious keyword SPAM isn't going to garner top placement anymore. Don't even bother creating and hiding meaningless sentences that do nothing but repeat your keywords. Focus on your title, headings, and building link popularity instead.