You can spend every waking moment promoting your site, but if it's not a well designed site to begin with, you're fighting a losing battle.
Good sites help to promote themselves.
Slow Download Times . You can have a site that provides the best content in the world, but if it takes forever to download no one will hang around long enough to view it. As a general rule, the longer it takes your site to download, the fewer visitors will stick it out 'til the bitter end to see it. The next time you're tempted to take that 8x10 photo of you at age 5 with Bozo and turn it into a clickable image map, it might be wise pass on it. When visitors hit your site, they're looking for information, services, or products.