There is one important monetization strategy that is overlooked by this article: dual licensing. License the source explicitly for non commercial use only, then offer a commercial use licensed product (plus support, usually) for a fee. If there is a big community of hobbyists in the relevant field who do the same thing in their dayjob, I think this works well.
Edit: A more open source version of this is to GPL the source and offer a more commercial friendly licensed product for a fee. I don't know if this technically goes against GPL but I have seen people do this.
Edit: A more open source version of this is to GPL the source and offer a more commercial friendly licensed product for a fee. I don't know if this technically goes against GPL but I have seen people do this.
Edit: https://en.wikipedia.org/wiki/Multi-licensing