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]
(..) A rat hole, is a friend, like Brad here. Who held stock in his name for me. How are you doing? Goodbye... I drive the price up, then he'd sells and kick most of the profit back to... you guessed it, me! All cash, none of it's on the books. A big no no of course in the eyes of the law. (..)2013 The Wolf of Wall Street
(..) Now, right now, John, the stock trade over the count of cent a share. And by the way, John. Our analysis indicated it can go way hack of lot higher than that. Your profit, on a mare $ . investment, would be up to $ .. - Jesus! That's my Mortage, man. - Exactly. You could pay off your mortage. (..)2013 The Wolf of Wall Street