When Eric is describing having to wake up at 5 am and work weekends to make Code Sponsor work even with the proceeds of 60% of all OS projects his ad network funded, it should be pretty clear the other 40% divided among many OS coders couldn’t be enough for their project’s development to feel sustainable.
As much as I commend Eric on trying to find a solution to OS maintainability, I think he actually just reinvented something already available to OS developers, a niche tasteful ad network, I.e carbon ads <https://carbonads.net> something which many OS projects with a large enough audience already include to support development.