This is making me think why stop at software solutions? Why not just solve business problems in general, but use Ruby on Rails as a tool to solve them? Maybe some problems won't even need Ruby on Rails!
Another questions comes to mind: how would I sell a service with such unpredictable outcomes? If I sell software, then I can almost guarantee certain features. But if I were to promise "more customers" or "more sales", I wouldn't even be 100% sure myself if my methods will work. How would I market a service with an unpredictable success rate?