you could visit a site someone in here told me about called evreward.com http://evreward.com/store/index and use that to both get a discount listed at any store, AND get the miles for buying through them online. As well, should that particular store be offering some online discount like free shipping or spend X to save Y, then you coudl still do that too!

In the non mileage world, I know if you happen to have coupons from Linnens & Things OR bed, Bath & Beyond and you want to shop at either store, both stores will take each other's certs even if they are from someone else or are expired. AND you can use up to 8 coupons at once sometimes if done in a certain way. An example of this is if you bought dining room chairs there. Make 8 sep. transactions and save more than you would if you did one big charge and used only one coupon.

And use a miles-earning CC too.