Rewards get taken away from you without being notified.
I had cash rewards card from boa with 2% flat cash rewards back on all purchases plus 25% more if I let it accumulate it beyond $300. I used it for more than 4 yrs and cashed out 3 times in past. Just this month i lost all my bonus and $340 rewards becoz they cancelled my reward program and changed it to their new 1-2-3 program. In future, you might lose too. I complained 2 levels up and still no resolution.