I was suggested applying for a membership card at a store I go occasionally. They told me that there are two types: Cards thatI can also use as a credit card, and cardsI use only as a reward card. With a credit card, I can enjoy more special favors than just a reward card. However, I own minimum numbers of credit cards; it's my principle. Besides, I considered the frequency in use of this shop and the disadvantages of NOT applying for the card. And I thought there would not be much difference between having just a reward card and NOT having either of them.