I didn't want any license for the makefile, as it's more of a utility then source code. However after looking around it seams that it's hard to release things into public domain anymore. So I picked CC0 which is basicly public domain.
You can use the makefile in anything you want, private, open source, commercial closed source.
The makefile does start with the license, however this was just done to try to make it clear that you can do whatever you want with it (oddly leaving it blank, makes it unclear if you can use the makefile or not, go figure).
Mostly by spreading the word / linking to this website.
I don't. I did this as a project of interest not to make money. I don't see making any money off this project, and I'm happy with that.