Bill Slawski digs into a new patent application from Microsoft that aims to include the age of the domains that link to a given Web site as part of the site’s overall ranking criteria.

The patent, called “Ranking Domains Using Domain Maturity” was published last week (but filed in late 2006), and assumes that newer domains have a higher likelihood of being spam and/or being part of a link farm–and should be judged accordingly. Thus, sites with a high influx of links from older domains would ultimately be ranked higher than sites with a host of links from newer domains.

Slawski explains the logic behind the patent, noting that both the ability for domain-buyers to try a domain for up to 60 days (in some cases), and the low cost of purchasing a domain have combined to create an environment where scammers can set up link farms and other spam sites with ease.

The patent offers multiple options for ranking sites this way, from gauging the number of links from mature vs. immature domains, including the links from mature domains only, or using link domain age as only a percentage of a Web site’s overall rank. Read the rest of the story at his blog.