As has probably been said in the pages I haven't had time to read, it's an interesting theoretical exercise till you actually redeem them.

My husband had 109,000 miles that were about to expire last year. I bought a $25 iTunes gift card through aa.com after logging onto his account to keep the account active. The 25 miles we earned saved the 109,000 miles from expiring and we just redeemed 100K for a Business Class ticket to Europe. We paid for an identical itinerary for me, and it was $3,300. So, by my calculations, we yielded $132 per AAdvantage mile on the 25 miles from the iTunes card!