The older the site, the more authoritative it can get from search engine's point of view.Time is the ultimate distinguisher between builders and spammers. Spammers come and go, hit and run. They are always impatient, looking to make the quick buck with a spammy site. Once they find it's not profitable, they'll stop renewing the domain after the 1st year. Google knows this too well.So most of your sites would not actually start performing in terms of search engine traffic until at least 1 year after domain registration. Yet most people are too obsessed with quick results and never wait that long. They kill their sites just before they can make them decent money.