Neat things I like about it:
1) Is the app branded for my store?
Yes, you send us your logo and color choices and we design the app!
2) How can I track customer usage of the app?
SnowShoe has a merchant login, where you can sign in and see all your customer usage statistics on an hourly basis.
3) Like the title says, it will work on smartphones without NFC.
A couple things I can see holding this back, though.
1) It looks pretty bulky. Might not be a huge issue for the intended use of having it at a business checkout, but carrying it around for non-traditional storefronts or businesses, the thickness could be a holdup.
2) Do I have to post to a social network?
No, but if you want to get your free item faster you should. Each time you share a post you will get an extra punch!
3) It only works on smartphones. Even worse, it only works on iOS devices and Android 4.0+. Even worse, it only works when the app is running and the phone is connected to an Internet connection (wifi recommended).
NFC works, at least on my phone, all the time. You tap the phone and it launches the NFC-enabled app. The guys and gals at SnowShoe seem bright, talented, and fun. I wish them all the best with their products, and this definitely is a cool and trendy device with some interesting hardware and software working together to make the magic happen. I do have to say I prefer solutions that are a little more cross-platform. As a Windows Phone user I'm used to being left out in the cold, but NFC wallets have this beat and with a simple app you can replicate the rest still using NFC. Time will tell if NFC actually grabs any hold in the marketplace, though.
--edit: not that this post isn't long already, but I thought I'd add one more thing. I love the concept of capacitive stamps. Even not knowing where this specific product will end up in the marketplace, I think capacitive stamps could have a future for myriad purposes. It's now on my list of "why didn't I think of that!" ideas.