Hungry Jack's Implements Shake and Win App for Freebies

This is probably the cleverest promotion I've seen from a fast food company in years!

Hungry Jack's has come out with an iPhone App which gives away free food items every day to potential customers within 1km of any Hungry Jack's store. Once you are in range, activate the app and shake your phone to find out what the closest store is offering you. Let's say you win a Whopper, the timer will start counting down from 20 minutes during which you are able to claim your giveaway.

This is a clever app because it is not just giving away free food items.

1. Hungry Jacks is making people more consciously aware of their stores nearby. The more you have HJs in your head, the more likely you are going to stop by. 
2. By offering a giveaway with a time limit attached to it, they are turning their foot traffic, or rather, road traffic, into more potential sales. The countdown introduces a fear-of-loss aspect to the giveaway, leading to more spur of the moment purchases than they would have achieved.
3. The app also promotes the fun side of Hungry Jacks, requiring customers to shake their phone to get their deal. Potentially, this can make people more likely to talk about the offer to friends that are nearby. If you have a school near HJs you can imagine kids shaking their iphones at 3:30pm seeing whether they should drop by HJs with their friends
4. Having the app only available on iPhone means that there will be another flurry of interest when it finally gets developed and released for Android users. 

So what do you think of Hungry Jack's app strategy?

EDIT: If you have a Samsung Galaxy II or III, Galaxy Nexus or other Android phone, the Hungry Jacks shake and win app is now available for download as well! Check it out here.

6/10/12 - It seems that this promotion is over. Quite a few stores that we tried recently all said "Sorry all prized have been claimed at this location for the current time".