This is due to the nature of my dh's job. Idine gives you 15 cash back if you use cc registered with them and dine in their restaurants. Since our dining expense around 4000 a month, every month we are getting idine cash card for the rewards in amount of 400-500.
I perfectly understand that most of the people do not have this kind of expense. It would be madness to waste these money in restaurants, instead of the plane tickets.