Some SEO factors are beyond improvement and optimization, like domain age or website age. A company that has a 10-year-old website with a good domain name (say “childrenbooks.com”) is in theory ahead of another one who just registered its domain name (say “childrenbooks.net”). But why, in theory? And how Google values domain ages? What else is involved (with SEO effects)?
Matt Cuts, from Google, said once “the difference between a domain that’s six months old versus one-year-old is really not that big at all”, so he confirms there is a difference, he just doesn’t say which. But the interval he uses is small (6 months), so the more old a domain is, we believe the more importance it would have for SERP (a 10 year difference would be something really meaningful). In the patent “Information Retrieval Based on Historical Data”, of 03/31/2005, Google states that domain age is a signal used to verify legitimate domains and also as an indication of value. It says:
“(…) the date that a domain with which a document is registered may be used as an indication of the inception date of the document.”
Attention to “may be used”.
Another piece:
“Certain signals may be used to distinguish between illegitimate and legitimate domains. Valuable (legitimate) domains are often paid for several years in advance while doorway (illegitimate) domains rarely are used for more than a year. Therefore, the date when a domain expires in the future can be used as a factor in predicting the legitimacy of a domain and, thus, the documents associated therewith”.
Again, highlights on “can be used”. We don’t know if it’s an algorithm-based decision to use it or not, or if it’s just a patent statement. Cutts affirmation leads us to believe it is in use.
Anyway, more important than domain age for SEO is website age. The longer Google is recording content and movement (i.e., backlinks) in a domain name, the more importance that domain will have. That seems to be a fact beyond speculation among SEO professionals. We know that by our own experience that it counts and it has high relevance. But, of course, it is among all the other factors, like keywords in content and title, inbound links, etc. In that scenario, even a super old domain can be easily surpassed by a new domain if this new one has better content, more inbound links, etc. A job well done has it all.