I had never considered that a paying SaaS could be open source and that raises some questions to me, like: 1. Why would people pay instead of just downloading your code and running it for free? 2. Couldn't anyone grab your code, tweak the UI to make it look different and then sell it as their own SaaS which would be your competitor taking some market share away from you with your own code?
1. Most folks interested in a saas probably don't want to host it themselves.
2. Code needs maintenance and expertise to run. Could you download the source of a large app and compete against it profitably? Maybe if it were mature, well documented, and longtime contributors hired.
