Axandra (http://www.axandra.com/), a German company, has studied which factors affect high rankings in popular search engines, including Google, AllTheWeb, iWon/Inktomi, Wisenut, Teoma, and AltaVista. Their April 2002 "Google Ranking Study"  looked at the characteristics of pages that ranked in the top 10 for 1,721 popular keyphrases.
Johannes Selbach, cofounder of Voget Selbach Enterprises GmbH, says about the study: "We want to give our readers accurate data on what kind of web pages Google (and other search engines) currently rank in the top 10 so that they can make their own conclusions." 
For example, most results pages on Google ranking in the top 10 have these characteristics:
Have zero or one matching keyphrase in the title or h1 tags.
Have head sizes from 50 to 700 bytes.
Are older than three or four years .
Use two or three meta tags.
Average 20.4KB per page.
In addition, the following is true of the top 10 results:
Nearly 85 percent have search term densities of around 0 percent.
94 percent have search term densities of less than 5 percent.
4.3 percent use Flash or Shockwave.
Less than 3 percent use Java.
Over 81 percent don't have search terms in hyperlink URLs.
So the typical high-ranked page on Google is over three to four years old (this provides external links to your site), and low-tech (few use Flash or Java). It uses two or three meta tags in a trim head from 50 to 700 bytes in size , averages around 20KB, and uses keywords sparingly. Fat keyword-filled pages clearly don't rank well on search engines like Google.
There's an entire industry of firms that are built around attaining high search engine rankings. Some of these firms are bogus , while others are legitimate . Choose wisely, because the reputation of your site may hang in the balance. By applying what you've learned in this chapter, you'll have a solid keyword foundation that will attract qualified customers interested in buying your products instead of undifferentiated traffic.