Thanks to Terry White for saying this so well:
”Apple released the details on getting your $100 Apple Store Credit if you bought AND activated an iPhone before August 22nd. I have to admit that I was expecting Apple to make it harder than this. I was expecting to download a PDF, fill it out, mail it in and wait 4-8 weeks for a snail mail certificate. Apple could teach the world how to do rebates! Go to the link above on your computer and you basically enter your iPhone phone number and serial number. You then get a SMS text message on your iPhone with your code. You input your code on the same page you were on above and a couple seconds later your rebate certificate is there in your browser (on your computer) for you to print!”
Kudos Apple, the whole process took about 15 seconds and now I have two $100 store credits (for our two iPhones) in my hands!