Hi I am giving away a bunch of promo codes (35) and can across this http://fredandrandall.com/PromoURL/ helps you distribute the codes (people click on it and it sends them straight to the appstore with a new code... so they don't have to keep trying each code until they find a working one). Seems like a nice way to do it...
Not sure it works 100%... I started with 35 codes and they where all used by the dispenser... but my analytics says only 20 codes where used... I think as my app is over the 3G limit then it won't download if you are on 3G and then there is no way to get the promo code back (or check to see if it works).... so good if you are under the 3G limit but problematic otherwise...
^ It seems to work that whenever the link is clicked, the site considers a promo code to be used, regardless of whether or not the user actually redeemed it