You’ve heard the old adage, “Age before beauty.” Well that is very true in the world of search engine optimization. Search engines like old mature URLs. They will rank two equally-optimized and well-designed sites differently based on how long the URL has been active. Why is that? Well only Google really knows.
But if you think about it older domains have the benefit of many years of accumulated natural links, they have time to create a library of relevant and quality content and have been well indexed.
Using domain age as a ranking factor helps weed out the lower quality churn and burn type websites that are trying to game the system and tend to be more spam than substance. It makes sense that Google would want to avoid rewarding these sites.
But don’t think you can just jump ahead of the line and buy an older domain name. This may work, but more times than not Google will be wise to what you are trying to do. Google is aware of when most domain names change hands and these sites seem to mysteriously reset. You also have to be wary of the old domain name’s history. It may not have been a reputable site and you could inherit its baggage rather than benefit from its age.
Your best bet is to get your domain name up and running as soon as you think you are going to start a website. You want it cooking for as long as possible. Don’t feel like you have to wait until it is perfect to get it going. After all, who is likely going to see your site while it is under construction anyway? Until you start your SEO efforts in earnest, your site is likely to perk in blissful obscurity until you are ready to announce your presence to the search engines and the world.