Ugh I've gotten a bunch of the codes over the past 2 years and, of course, now that I have a trip planned and can actually USE one, I don't get one! Grrrrr
One thing you can do to help your chances is go on the Disney website and create an account. Make sure you check the box that says you would like to receive information from the company. I've heard ordering a planning video might do the trick too.