In the midst of research for Monday's post, Buying Back Expired Miles, I stumbled upon some information from milecards.com that mentioned another way to earn back expired American Airlines miles via a Re-engagement Challenge. For frequent American Airlines/oneworld flyers, participating will be cheaper than paying to get larger amounts of expired miles back.

The general gist is that if you have miles that expired within the last five years, you can pay a flat $30 fee to register in a "Re-engagement Challenge".