The overwhelming majority of my customers are on the online version now, since I've exiled the downloadable version to electronic Siberia. If no customer ever found it again I would be happy.

With regards to marketing, see my blog (www.kalzumeus.com), but the short answer is I use organic SEO and AdWords. My one trick pony for organic SEO is scalable content generation, and what a beautiful, loyal pony it is.