Project size
I'd be interested to know if project size was considered, and whether this would make any difference if factored in.
The way I tend to work is that I'll license smaller projects and things that don't have any potential for commercial exploitation under a permissive license (I tend to use BSD 3-clause), but for larger or more important projects I'll tend to use GPL.
If others do the same then you'll have a million small projects using permissive license and a handful of large projects using GPL. That could affect the numbers in a study like this if the size of the project isn't being taken into account.
Biting the hand that feeds IT
