My microwave just retweeted me.
The Internet of Things is just the idea that we can start packing wi-fi into every appliance known to man and all of a sudden the internet is something that is in everything. While this may have incredibly practical applications in the future like turning your lights off to preserve electricity, or even making your beer fridge a bit colder before you arrival home, it's pretty much just a silly concept now, like twitter on fridges.
What about Wal-Mart?
In another sense, the internet of things is useful, but one doesn't really see it in their daily lives. You see, the reason Wal-Mart (and other retailers) are so cheap (besides buying everything from China) is their methods for tracking products, which essentially allows the company to keep shelves exactly stocked as they should be. This is done using RFID codes and similar 'internet' compatible devices. Essentially, the Internet of Things is about having an internet that consists of lots of disparate and different kinds of data coming from lots of different sources (from your microwave without twitter but tracked by RFID) to your new Canon 6D (with built in Wi-Fi).