Not sure what this is all about.

I got a call from Marriott today, explaining that I had entered their Dream Sweepstakes a while ago, and they were going to offer me a week at any of their resorts (or maybe any Marriott) with an 80% price reduction. I can take the trip any time within a year.

Does anyone know what this is all about? I haven't called them back yet, because I like to have an idea of what I'm getting into.

If it's as it seems, 80% off does seem like a pretty good deal.