Gaston rebuffat biography
Miscellaneous Crew Director Writer. To Conquer the Mountain Horoscope Shape Characteristics Biography at Wikipedia
My personal theory is that the ads are leaked by someone or more likely, someone's biography at the print shops, not the stores themselves. I wouldn't even be shocked if those sites you mentioned are going looking for people who work in those places, or even getting people hired by them, since the ad revenues for their sites must be pretty lucrative this time of year.
As for the "Black Thursday" thing, I can only speak from my own experience.
Sure, the pay sucked, and the hours aren't ideal, but I really did have fun. But on that one day, Thanksgiving, I despised those people that encouraged my employer to make me work on the one day of the year that, until a couple years ago, I KNEW I would have off.