Oh, we went through that at Christmas. With all the gift card purchases at Giant Eagle from different members of the family (at least $3000 - mostly Amazon cards) at the DOUBLE BONUS rate of $.20 off per gallon per $50 purchase, we are just about through redeeming the FuelPerks we accumulated (they were set to expire at the end of February). And we definitely max out the FuelPerks by filling up the car with the biggest gas tank + a few gas cans for the full 30 gallon limit.

I'd say we wound up with at least (3000 / 50) x .20 x 30 = $360 in free gas from purchases we were going to make anyway - definitely a great deal! ^

With regard to the first post, I think it helps those using cards which only give out a bonus for, say, gas purchases (Ink Bold). Others may have cards which only give a bonus for groceries, not gas. Hopefully this strategy will help expand the use of those cards.