Money, mostly.
People who are driven only by money in life are pretty sad people, I think.
In fact, if you only measured success in monetary terms, you would likely live a pretty crappy life.
I am afraid they can become greedy and want to have more and more money even if they already have a lot of money. Life needs to be balanced. If we have money, it is better to give some money to people who needed. Maybe family can motivate us to work hard every day, so we can share some with other people when we can have money.