Just be very careful and keep good records as to which portal you used for each transaction - over the past three months I have registered in both AA and UA mileage program where if you register your credit cards you get miles for shopping in the retail stores - although I have shopped in many of the stores, not one mile has posted yet. Also, to keep some accounts active I have used the shopping portal and out of 15 transactions, only one came through. I was very careful to re-boot my computer and clear my cookies and cache before starting the transaction so there would be no confusion. I am still waiting for the miles from AA for the Dell computer I purchased, as well as purchases from Brooks Brothers, Lands End and The Walking Company.