I'm honestly not sure how the codes are generated. I got one for 20% last year which I was not able to use and one for 40% this year which meant my brother and I absolutely were going.
All I can say is that I am registered on Disney.com (and disneymovierewards and disneymovie club). I have a profile entered and have indicated some of my favorite resorts, attractions, etc..
I visit the site occasionally and both this year and last year, have priced out vacations online. I have not booked them online, but I did use the site to price out different dates, resorts, etc. Now was it because I got a 20% code last year which I did not use and continued to look for vacations that I got a 40% one this year? I don't know.
All I can recommend, and many people have said the same - register for as much as you can, but I would also add that you should visit the site. Maybe, possibly it has some small effect????
