Agreed. I am working on one :) I just meant that if you are addressing developer market, sales costs are lower as developers live on the web and there are many mediums to share information such as hacker news.
I find that other parts of the enterprise market are surprisingly harder to reach. In enterprise companies information sharing is often discouraged, many folks working in the enterprise are hesitant to mention what products they use let alone promoting (or criticizing) them. Successful SaaS companies addressing the enterprise seem to either gain traction elsewhere and then try to penetrate enterprise or spend tons of money for marketing and sales.