Just to confirm, irrespective of whether modding becomes more monetised or not, I plan to always position the Nexus as a completely free modding resource, free of monetisation. Modding, for me, is a hobby, not a career. While careers can spring from modding (by being hired by a game developer), money should not be the main motivation for it.
I look at the subject the same way I'd look at football. All professional footballers start playing football as a hobby. They don't get paid for it. If they're good enough they're scouted by the football clubs at which point football becomes a career, not a hobby. Feel free to poke holes at my analogy
