Originally Posted by
FriendlySkies
Unfortunately, that deal is dead.
Yep.
Per
http://mileageplus.topguest.com/
Thank you for your participation in MileagePlus® social offers.
This promotion ended on June 15, 2012. Registration has closed and MileagePlus award miles are no longer being offered for checking in via Facebook or Foursquare at United airports.
We hope you will continue to take advantage of the many other ways to earn MileagePlus award miles. To learn more about earning and using miles, please visit mileageplus.com.