Heads up, travel hackers! Avianca LifeMiles is offering a sweet 15% bonus when you transfer your American Express Membership Rewards points. That means for every 1,000 Amex points you send over, you'll get 1,150 LifeMiles instead of the usual 1,000. It's basically free miles! Why should you care? Well, LifeMiles can be awesome for booking Star Alliance award flights (think United, Lufthansa, etc.). Sometimes you can snag flights for fewer miles than booking directly with those airlines. If you've been eyeing a trip and have a stash of Amex points, now might be the perfect time to top up your LifeMiles account and make that dream vacation a reality. Just remember that transfer bonuses like these come around fairly often, so if you don't have an immediate use for the miles, it might be worth waiting for another offer down the road. There is no current end-date for the promotion.