I'm surprised somebody as generally savvy as Brian Lunduke is trying the above approach.
To Mouser's point, releasing under GPL is
not a business model. It's a
development philosophy. Attempting to "monetize" such a philosophy is much like attempting to run a "for profit" non-profit. In short, it's an oxymoron. And all the semantic hairsplitting and tap-dancing in the world won't change that.
Simple truth - no matter what 'open' license you release under, it's tantamount to giving your code away. Which is exactly what most open software licenses are designed to accomplish. They make code freely available to "all mankind." And the only restriction is it forbids anybody from asserting
exclusive ownership of the code in question. Sound like a silly license if you're in business to sell an app? Sure does to me.
Several businesses have tried what Brian is suggesting. It generally doesn't work for a single smallish app.
Where it does work is when somebody is providing
configuration or
integration services for a bundle of apps that would be extremely difficult for the average user to get working correctly. Highly "vertical" distros that provide immediate out-of-box high level functionality are good examples. Turnkey music studios, network appliances, app servers, and media editors/compositor collections have all been successfully bundled and sold as turnkey binaries. But that's selling a service and expertise. Which is not the same thing as selling a single app binary.
And even then, it's only a matter of time before somebody uploads your binaries to the torrents. And it's questionable (to the point of doubtful) that you can legally prevent somebody from doing that under the terms of the GPL. Or was last I checked when the question of whether it was ok to wrap a restrictive or proprietary installer around GPL-ed software came up. (Note: I'm not a legal expert so I may be wrong on this point.)
I wish Brian the best. After his fiasco with Apple's App Store (which almost broke him) he deserves a break.
But I don't think his latest brainstorm is going to give it to him.
And I sure hope, for his sake, I'm wrong about that.