Those are indeed very positive-looking DVD sales that, by most historical measures, virtually guarantee a sequel if it keeps up. So good news for all.
I received my own copy of the DVD this past week, and (as we knew from the solicitation) it contains a number of nice extras, including a puzzle, an illustration card, and an 8-page full-color booklet. Confusingly, it also comes with two different mail-in offers, and there will be three different offers over the course of the DVD release.
Offer 1: Collect DVDs 1-3, and you could win 1 of 250 DVD Boxes (to house the series)
Offer 2: Collect DVDs 1 & 2, and you could win 1 of 250 tickets to a live event featuring members of the cast
Offer 3: Collect DVDs 4-6, and you could win 1 of 250 Original Bumper Stickers
I'm going to try for the DVD Box myself, but with sales being as high as they are, I have to imagine that my chances of winning are pretty darn small. Plus, it'll cost me like $50 for the attempt... *crosses fingers, toes, etc...*
