I've added a feedback system to the forums similar to ebay and what not to try to improve the experience of doing business on AA. How do I use it you ask? It's pretty straight forward. You can technically submit feedback from any page, but logically you'll be in the Buy/Sell area when doing it. Simply find a post from the person you did business with and underneath his name you will see "Trade Count ()" with a number listed in the parenthesis. A positive number indicates an overall positive feedback and a negative number indicates an over all bad feedback. Clicking on the number will give you more details about the feedback as well as allow you to submit feedback for the user.
Feedback is broken into 3 groups, Buyer, Seller, and Trade. Once you click on "Submit Feedback" it will prompt you to enter YOUR role in the deal, if it was positive/negative/neutral, a short comment on the deal, a URL/Link to the ad in question, and a long comment on the deal. Once you click the "Submit Feedback" button your feedback will be sent for admin approval. The deal doesn't have to be completed for you to leave feedback. If a party drops out after agreeing to a deal, doesn't show up, whatever, feel free to leave feedback on that.
If someone has left feedback for you that you want to dispute, please PM me.