Just on groceries that is a free flight every couple years. Of course I also buy clothing, phone bill, car repairs, birthday presents... In short, I charge almost everything. I'm going for the 1% cash back not the points, but to me it seems normal to be getting back more than $100 every year. Note that I do not carry a balance. Everything in that list is something I do anyway, and I have the cash sitting in my back account (so I should probably add another buck to the $100 above for interest in my bank accounts)
Note that you have to be able to control yourself. If you ever carry a balance the math fails.