Getting users 
patio11: Content creation and organic SEO.  If you're the guy writing things that solve problems for your users, it a) brings them into your site and b) pre-disposes them to trust you when you say that using your software/service will help them with the problem they are having.  (Content ranks for long-tail terms, content draws links, links help you rank for more competitive terms, repeat ad nauseum.)Organic SEO scales stupidly well, incidentally, and if you're a bootstrappy type of person you can turn the revenue it brings into AdWords or other paid acquisition strategies, then use the revenue that brings to improve your organic SEO, then...It really helps if you either write very well, have a unique positioning for your blog/articles/whatever, or have some sort of unfair advantage that everybody else on the Internet can't match.  In my case, the unfair advantage for the last two years has been my CMS, which lets me outpublish organizations with budgets next to which mine would be rounding error.  (An old buddy of mine, ex-military, on the subject of unfair advantages: "A fair fight is the result of poor planning".)