There are a small number of OSS companies you can point to as being successful. Mozilla is successful, but basically their revenue comes from Google. So certain

There are a small number of OSS companies you can point to as being successful. Mozilla is successful, but basically their revenue comes from Google. So certainly one lesson there is to find a single giant benefactor. Google, Facebook etc do have open source code, but not their "revenue earning" product. So perhaps the lesson there is to make lots of money somehow else and use that to fund your OSS projects. MySql was kinda Open Source, but their license violated OSS principles. So the lesson there might be "call it Open Source, but lie". Red Hat took a project made by someone else, avoided the development costs, and monetized packaging and support. (The then pushed some of that revenue back at the upstream projects.) So I guess the lesson there is to minimize development costs and maximise marketing. None of which negates your point that some small number of companies have found success. But I'm not sure this helps random developer monetize their OSS project today.