If I recall Jeff and Joel, in one of their podcasts, said their ideal situation was that people would visit the site via Google. They acknowledged that they did

If I recall Jeff and Joel, in one of their podcasts, said their ideal situation was that people would visit the site via Google. They acknowledged that they didn't think they could improve search beyond what Google offered and expected / intended for the overwhelming (I think they said it was something like 95%) number of vistors to be from Google.