Right now you can earn 500 bonus United miles for every $250 purchase through the MileagePlus shopping mall. The maximum bonus is 2,500 miles. Offer ends at midnight 12/31/12.
Is this a good deal?
I’d say yes, especially considering that it sounds like any retailer on the United shopping mall counts toward this bonus. Unfortunately United is not very generous when it comes to the actual points per dollar that you earn for typical purchases. However, if you consider that you earn 2 miles per dollar spent on top of the normal earning rate, then you are doing pretty darn good.
My only advice is to keep a good record of your transactions through their shopping portal. The portal is run by Cartera Commerce who has a horrible track record on actually posting your miles. United ran a huge promo last summer where customers could earn up to 1,000 bonus miles for only 2 or 4 $10 transactions, but many ran into issues where Cartera either never had a record of the transaction, or neglected to post the points.
In any case, this is a solid promo and one that you should max out at $1,250 spend if you are able to.