I have been using my Discover card when purchasing gas lately because I get cash rewards with them. A few days ago I noticed one gas station I sometimes go to now charges more money, about 5 cents more, for gas if you pay with a credit card. I will no longer go to that gas station.

The gas station closer to my house does not do this, yet...however, it seems as though more and more gas stations are so it could only be a matter of time. Take a look around and see if you notice this trend. Be careful, some signs do not reflect this price hike and many people aren't finding out until they go to pay. The prices shown reflect CASH payment, which I feel is misleading. They get you to buy gas from them based on the price shown, unaware that the price is only for paying with cash.

Apparently, gas stations are “forced” to adopt this policy because merchant fees eat into their profits.
Great.