He declared in that book that his games sell 6 figures a year ( 100.000 - 900.000 usd )
He has 10 new games in his catalogues
If I take his words literally we are not far away from a turnover ( annual revenues of his company , not number of copies of course ! ) in terms of milion dollars

Should his turnover be of " only " (sic) hundreds thousand dollars ..well in my opinion he his a pro
The difference between mr Vogel ( a pro ) and me ( an amateur)is :

He can afford to spend the whole day in game programming ( me some hours a week )
He has 20 years experience in game programming ( me just 3 - 4 years)

Consequently I dont try to do what mr Vogel does ( not to mention Oblvion )
I prefer to focus on small casual games

This is my 2 cents suggestion to the newbies