Have a great Product - its as simple as that.
I hear so much about marketing these days as everyone seems to be an expert. Thing is that if you have a great product then it will finally find its way to the right people. In the past it was word of mouth but in our new Web 2.0 and social media world, word of mouth is word of the web. Very powerful if your product is great. If your product is not great then run for cover, any amount of "clever" marketing is not going to save you.