Shell Credit Card – a Good Deal?

I was at the local Shell station yesterday and an advertisement for their credit card caught my eye. The promise of 15% off gas for 2 months (and 5% after that) should interest nearly everyone. In the past, Shell would charge an annual fee for their card, which negated most of the benefit. However, this seemed like it was free. I have to read the fine print to make sure.

I already have a Chase card that gives me 5% back at all gas stations, so after the promotion period, there’s not much of a need for the Shell one outside of $0.35 off per gallon. Doing a bit of math, my savings should be $25 during the promotion period with typical gas usage. I would save only $8 if I used my current card.

Assuming there aren’t any “gotchas” in the offer, is it worth it to get a credit card for two months?