Not really any alerts that I'm aware of, best is to follow FB groups and boards like this, but you can also check out mouse savers.com for historical discount data-based in past history you will have some idea of when to check back for Dec next year. Also if you play around on the Disney go website plugging in dates and such-leaving a trip in the cart sometimes you will get email notifications(reminders to book your trip) and then surveys to follow, some say this increases your chance of getting a pin code mailed to you for a promo