Depends on the site. A site offering customized Christmas cards won't do well immediately if you launch in January; a site offering something useful for prepar

Depends on the site. A site offering customized Christmas cards won't do well immediately if you launch in January; a site offering something useful for preparing for college won't do well immediately if you launch in November. Launch the site as soon as it's ready to be launched. You'll drive yourself crazy trying to micro-optimize and asking yourself if you'll get more traffic if you launch on Tuesday or Saturday.