They are not actually giving away free membership, but rather helping your elite points increase, and thus give an incentive to buy a little bit more, on each order.
10,000 pts is the equivalent of 1,000$ in purchases. That is a substantial amount for most buyers, but it accumulates over time, so if you are patient enough it is within reach for most of us. If you crave for a specific prize (some of the low-end decks or uncut sheets for example) and you lack about 100 to 200 pts, you might just buy one or two more decks with any purchase just to hit that target and snatch that prize sooner. But if you are just starting to collect points, you are just so far that you won't be tempted to buy more, you might even think that the membership is out of reach.
The holiday wheel helps buyers progress in a way that teases you to hit milestones. It helps you get started faster and start dreaming about that or this prize that is now just a little more accessible, or it gets you just additional points to get you start dreaming about that membership card. So you start dreaming and wishing, and then you buy more (we all saw that happen with the iPhone initially...).
So, I think the holiday wheel is a good thing for T11 overall, as more customers will buy more (I know I do). And with releases such as the Limited Mailchimps this year, we, as buyers, will have more and more reasons to want that membership card.
However, as more and more people get that 10,000 mark, I wouldn't be surprised if new membership levels see the light of day, just light like most frequent-flyer programs are doing with bronze, silver and gold memberships.