It depends on the business. That model definitely works, and another variant on the model where paid solution users get additional enterprisey features also wor

It depends on the business. That model definitely works, and another variant on the model where paid solution users get additional enterprisey features also works (single sign on, Active Directory integration, etc). Take for example Chef, which has a paid version and an open source version. Paid Chef comes in 2 flavors, hosted and on-prem. There's also Nagios and several other IT monitoring solutions. You may want to double check on which license is best to use in this scenario, but it definitely is possible to grow a business using it.