United MileagePlus is running a promotion (it may be targeted) where you can earn 1,500 bonus miles for completing a $50 purchase at any of their retail merchants on mileageplusshopping.com. In order to qualify you must register here.
The terms of the promotion state that you must register your MileagePlus credit card and complete your purchase within 30 days of registering or by Dec 31, 2012.
The terms also state that the bonus in only eligible to members who received their email, so who know if the miles will actually post. I’m going to register, since I already have a United MileagePlus Explorer card. Wish me luck!