Sign up for a 12-week print subscription of The Economist for $12 and receive increased bonus miles (for a limited time) when subscribing via the following shopping portals:
American AAdvantage – 3,000 miles
United MileagePlus – 2,400 miles
Alaska Mileage Plan – 2,200 miles
Southwest Rapid Rewards – 2,100 points
Delta Sky Miles: 1,800 miles
According to the T&C for this deal, you should be able to cancel after 60 days and receive the unused portion back as a refund.