This came in a mailing from airmiles.You may remember my post about bonus airmiles and Shell a little while back. At that time they offered 100 airmiles(our free movies and popcorn and pop gift certificates are on their way!) if you filled up 4 times with a $30 purchase each time. Now it's 50 airmiles and you need to spend $40 4 times. Last time I found it worth it as it worked out to $18.84(movie coupons)for 100 airmiles. This time it works out to $9.50. According to my calculations if I did what I usually do(fill up at Superstore)I'd get $5.69 in gas bucks for the same $160 spent. On top of that my credit card pays me 5% on my gas purchases so that's another $8. So from my point of view I would save(or make?)more($13.69-$9.50=$4.19) by doing what I always do. Plus, I wouldn't have to make 4 special trips to Shell.
It's always interesting to see how it all works out, according to your circumstances! Maybe it will be beneficial for you?