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]
(..) for the opportune moment. we found, but despaired of ever finding the last. When's that? When it's of greatest profit to you? May I ask you something? Have I ever given you reason not to trust me? Do us a favor. I know it's difficult for you, (..)2003 Pirates of the Caribbean: The Curse of the Black Pearl
(..) to brave all, hasten to her rescue, and so win fair lady's heart, you'll have to do it alone, mate. I see no profit in it for me. I can get you out of here. How's that? They key's run off. I helped build these cells. These are (..)2003 Pirates of the Caribbean: The Curse of the Black Pearl