He 'profited by' his experience/mistake. [=he learned something useful from his experience/mistake]
The book can be read with 'profit' by anyone who wants to understand how the system works.
We sold the house 'at a profit'. [=we made a profit when we sold our house]
(..) the military-industrial complex? Those are the manufacturers of the weapons. They think they own the system and they will do anything to keep that power. They profit off of your sacrifice. Politicians always love talking about sacrifice. Think I don't know anything about sacrifice? (..)2013 White House Down