I notice from the latest Iberia mailer that you are able to earn 3 Avios per Euro spent in Madrid's T4. World Duty Free Turn your Duty Free shopping into Avios Madrid Duty Free presents an exclusive deal for Iberia Plus members: shop tax free in Madrid T4 and collect Avios. Shop at Madrid World Duty Free and earn 3 Avios per 1 Euro spent. Flying to or from Madrid Terminal 4? Make sure you take some time to stop and shop on your favourite brands and earn Avios at the same time. Until 31 October 2016, shop on any of the selected Duty free stores in T4 of Madrid airport and, not only you will shop tax free, but also your purchases will get you closer to your next trip by accumulating the Avios you need. Dont forget to present your Iberia Plus card number when making the payment in stores. I also see that they are offering double miles or 15% off fares on their new route to Jo'burg and double miles for San Juan, Puerto Rico. I hope that helps someone.