Good suggestions...this is what I meant, folks. Let's assume I have a beautiful, fast front page (which I will have soon). My in-game has been considered good by players so far, based on player comments, and 8 of the 12 people who first signed up are playing regularly for 1-2 hours per day, so I don't think retention will be an issue, at least so far. Word of mouth is good too, but not if 12 people in the world know about the site.
My issue is that getting people onto and signing up for the site is harder without paying anything. Game Site Ads and Ad4Game are two i'll be trying, and contacting other site owners perhaps for paid ads or banners, game mentions in chat, etc is a good idea. Someone here said they got 800 people to sign up in 2 months, that's pretty good, and if I recall, that front page didn't blow my socks off really. Quality of the site AND quantity are both important, I think, when building a site's player base.