I have been running http://aminosoftware.com http://aminosoftware.com for almost 10 years now with a partner. It's not huge money but we do zero promotion and s

I have been running http://aminosoftware.com http://aminosoftware.com for almost 10 years now with a partner. It's not huge money but we do zero promotion and support amounts to a handful of emails a year and pays for my kids private school. Our customers are government and enterprise so purchase through invoice/PO paperwork but that's just a few minutes using a google docs template.