Well it depends on how you look at it.
If you just want the feeling of gratitude without any compensation.
Then yes; a smile makes you rich.
If you help someone save money. Yes, that smile also makes you rich.
If you help someone make money ; again that smile makes you rich.
So no matter how you look at it. A smile will make you rich.
Whether it’s a referral or compensation on someone’s investment; you will be grateful.