AAdvantage eShopping Mall is like other cashback shopping portals (eBates, TopCashBack, etc), except that they give you American miles as a reward. If you visit this promo link, it shows an offer that will get you 2,000 miles after you spend at least $35 at any store.
Now through 9/30/13 11:59 PM EST receive an additional one-time bonus of 2,000 miles when you shop through this email and spend a cumulative amount of $35 or more online in the AAdvantage eShoppingSM mall. [...] Please allow 8-10 weeks from end of promotional period for bonus miles to post to your account.
Earning miles this way will also reset your miles expiration date, which is 18 months from most recent activity. Via reader Jessica, who also points out that Peapod is an eligible store, so if you get grocery delivery from there that’s an easy way to get 2,000 points.