Just a sidenote, reading your comment it occurs to me that I have no idea - and as far as I can tell never read anything about - what is the proportion of code

Just a sidenote, reading your comment it occurs to me that I have no idea - and as far as I can tell never read anything about - what is the proportion of code that is done 'for fun' versus 'for pay'. If anyone has any survey or any discussion on that please reply so I can take a look at it. I'd like to confront my expectations with data