There is currently an opportunity to buy and earn up to 100% extra bonus United Airlines MileagePlus Miles. Before you cringe at the thought of flying on United Airlines, do remember that you are able to redeem them on Star Alliance and other airline partners. All you have to do is to enter your account number and last name to see how much your account was targeted for - the maximum bonus anyone can get at this moment is 100% and this is the best United Airlines has ever offered. Do note that all purchases have to be completed before 12 September 2017 in order to benefit from this bonus.