I've met with the founders of the project before. They really don't strike me as the bulls#$ng type of promoters we've all grown jaded over.
They love this project and what they do.
Can confirm that Square uses it internally
It seems to have been created by ex-Groupon folks, so that one is believable. Not sure about the rest.
It predates Groupon, was actually started at/around Ning (if anyone remembers them). Groupon hired a bunch of the core folks at the time they decided to adopt it.