Possible Clues:

• Popular firm and writer making profit
• The dough you get
• One might perhaps enter this for a living
• Money received on which tax is payable
• 1040 data
• Tips, e.g.
• In the firm it's myself that gets the pay
• Money from investments or for work
• Financial gain accruing over a given period of time
• Is it not capital that the M.O. turns up there?