This offer ends 11:59pm CT on Sept. 4, 2014.

Buy United MileagePlus award miles and get at least 60 percent bonus miles — and the more miles everyone buys, the more bonus miles you’ll get. Currently, there have been 2,554 transactions, which means the bonus is up to 60 percent. If more people continue to take advantage of the offer (at least 4,501 people) the offer will go up to a maximum of a 100 percent miles bonus.

You must buy at least 5,000 miles (at the cost of $188.13) during this promotion and can buy as much as 150,000 miles per calendar year. You can buy miles for yourself or as a gift to another MileagePlus member.

Go HERE to buy miles during this promotion.

INSIDE|Point: United is asking you to share this bonus offer with your friends and family through Facebook, email and Twitter so that everyone will get the full 100 percent bonus miles.