I worked for 5 years for a company taking from *BSD and not contributing much. Lately they started monetary donation, but no code.
That being said, unless you are already a committer, it's gonna be very difficult to get your code blessed...
Are there examples of this? Since I see people sending patches that aren't committers. I honestly would want to see some actual data.
but they aren't. GPL forces to release source, not contribute.