The old adage "older is wiser" seems to have some relevancy when discussing Web site rankings; old sites tend to carry more weight than newer sites. Take for instance the query "photoshop tutorials." In the first position is www.good-tutorials.com/, www.tutorialized.com/tutorials/Photoshop/1 is listed second. Looking at the Internet Wayback Machine, we find that good-tutorials.com was created March 23, 2003 while tutorialized.com was created February 6, 2004. Good-tutorials.com has the lower PageRank, page count, and far fewer pages in the Google index, yet still outranks good-tutorials.com. Through only a quick glance at the rankings for both sites, it seems that because good-tutorials.com was created over a year before tutorialized.com, its information is weighted more heavily. This becomes especially apparent when considering that Google's link count for tutorialized.com is over three times greater than good-tutorials.com and their page count is more than double. But there is more to this "legacy" factor than just how long a site has been around.
How many times a site has changed hosts, IP numbers, registrar changes, and the Whois history all play a part in a site's "legacy" factor. Whois records give us information regarding a site's history, basically acting as a background check for Web sites. Search engines take this information into consideration and tend to reward sites with a "cleaner" history. This is in large part due to various spam tactics used from past to present. Typically, spam sites will need to change IPs, hosts, and registrars to stay a step ahead of the engines. Because of this, spiders now look at Whois records to see how many times things have changed on a site. Typically, the fewer the changes, the better. If you have twenty IP changes within the last year, your site will likely set off some flags with the search engines. Your site most likely won't be penalized, but because of this history the site might not be getting all the credit it deserves.
This information can become extremely valuable when choosing a domain name for your site. In a perfect world, your domain should be one that is over a year old with very few registrant and IP changes. Older domain names typically experience a shorter wait time than newer sites to achieve high rankings. This means that you have to pay closer attention to detail when you go to launch a new site on an old domain. Because the older domain is already carrying some weight, it is entirely possible to gain rankings soon after launch. However, you also take the risk of losing these rankings if things aren't set up correctly. Newer sites, though they can take significantly longer to achieve high rankings (depending on how young the domain is), also have a larger margin for error. Because it's going to take a while for the new site to get in the indexes anyway, you can afford to not have everything perfect at launch. This isn't to say that any SEO effort should be completely ignored while the site sits; quite the opposite. This is the time to perfect any SEO campaign so that when the spiders do recognize your site, you don't have to build rankings from the ground up. You are constantly building history as well, so the fewer mistakes that are made, the easier it will be for your site to obtain higher rankings.