There are many things you can do to make your web page achieve high search engine ranking. Some of these things would be considered honest ("whitehat") while others may be considered dishonest or cheating ("black hat"). There are also powerful techniques and tools that fall somewhere in the grey, middle ground.

While you can apply many static quality improvements to your site like proper meta tagging and organizing keyword density and title tags on your site what will keep the spiders crawling and recrawling your site is fresh content. Every time you add new content to your site the spiders visit and find that the site has changed and the data centers must update their information on your site. Doing this often makes search engines such as Google consider your site to be very active which also means that it must be more relevant to readers. What few webmasters realize is that the search engines will believe the same thing about a website if the pages that the search engines already indexed are constantly being updated or modified.

Every time the search engine spiders visit your website and find that the content on your website has been modified, they realize that the entire site needs to be recrawled. A well maintained and frequently updated website is part of what search engines take into account when assigning rank to a website. While it may not seem like there is any difference in workload between adding brand new content to a website and doing extensive modifications to content that already exists there is, in fact, a large difference. It is possible to have existing web pages modify themselves automatically.

With a small change to the code on your web pages it is possible to have the content on them change with every refresh of the page. When spiders crawl the website they will see fresh content. The spiders will return after a period of time to check the web page to make sure their index is up to date and find that the web page has changed. This will cause the spiders to set a date for another crawl that is sooner than the last one. When they crawl again they will find that the page has again changed and as before they will crawl again even sooner only to find that it has changed again. Ultimately this loop will continue indefinitely although the spiders may limit the crawl time to daily or hourly.