He usually hasn't got a CLUE about Accounting. You cannot really promise him direct savings - in most countries and states that's forbidden as a way of promotion. The answer hits so close to your own area it's uncanning. Let me explain. You deal with figures.
Numbers are, in essence, symbols of other things.
Two plus two is four - but only theoretically. Numbers aren't the things - they only represent certain things. In Accounting, it's usually monetary denominations. It's a HUGE body of data, but let me give you some idea of this technique regardless. Instead, you use symbols.