Ah I see, that must have been the part at the end I missed. My audio messed up and i figured they would have said something like "donate to recieve the product" or something like that.
Hah, yeah. I didn't even watch their video.
Kickstarter offers different rewards for how much you donate, and in most cases where a company is hoping to fund a product they wish to sell, they tend to have the item as at least one of the rewards for donating.
For the Exploding Kittens fundraise, if you donate $20 (lowest amount) you get a deck of the cards, $35 gets you a deck of cards + a deck of NSFW cards (described as more gruesome/horrifying).
Then larger donations got you two of the $35 packages, but 1 is signed (for $100, but only 200 available).
And the largest got you the $100 award, plus the 3 creators each draw you a custom card (for $500, but only 5 available).
So, while not in this case since the additional Collecters Edition rewards are already taken, sometimes people continue to donate larger amounts in order to get a special edition or reward too.
I think in this isntance it's just people buying the product via Kickstarter, to save them missing out should it sell out once the product releases.