You can earn 8,000 Avios in Iberia Plus if you take out a 1-year digital and print subscription to The Economist. Its runs $160 for a print & digital subscription. Alternatively, you can earn 6,000 Avios with a $130 print-only or digital-only subscription.
You need to have an Iberia Plus account (sign up here: http://www.iberia.com/iberiaplus_en/). Once the Avios points arrive, you can convert them to British Airways or avios.com via the ‘Combine my Avios’ function online.
Tip: If you just want to maximize miles then wait for the points to post (4-6 weeks) then cancel your subscription and receive a pro-rated refund. According to: http://www.economist.com/help/manageprintsubscription#cancelsub – “To cancel your subscription, please contact your local print service centre. You may cancel at any time, and the remaining part of your subscription will be refunded.”