I admit, I thought they were mostly a gimmick when they first came out.
So did a lot of other posters - based on the responses to an old thread here...
Now, I see them show up more and more in the background in pictures of people's shops & under quite a few things people take pictures of.
I'm giving serious consideration to having my wife add a set as a "filler" item when she buys stuff from Amazon and needs a couple of bucks to make up enough for free shipping.