We make around 150k with our open source project too and there is no commercial license. Our revenue is from cloud and developer support. Maybe we should write a blog around that (https://erpnext.com)
Yes, that's the downside of making money with fully open source software - you have to find other means (support, hosting, ads...). But as an engineer - I really prefer to make money from selling the software itself - the thing I've created.
Please do; as noted above, lots of us would be interested in hearing the various stories of how groups have monetized open source successfully (and even unsuccessfully).
