Clarification, please:
Are you saying that the bonus dollars are awarded for INDIVIDUAL PURCHASES over $100? So that only a large purchase merits rewards?
Or are you saying that a TOTAL BILL FOR THE MONTH of over $100 receives bonus dollars? So that five $20 purchases would count toward the rewards?
Finally, just stating the obvious: Regardless of the answer above, this program is worthless UNLESS you pay off your balance every month. If you are paying interest at 18+% to recoup a 1% reward, you're losing money hand over fist. On the other hand, if you do pay your balance in full each month, it's a good way to save towards a Disney trip.