Source: What is Sunday?
Since we have names for all the days after Thanksgiving except Sunday, the Bloggess suggests we call it self-promotion Sunday. You could either look at that as a synical jab at holiday commercialism, or you could look at it as “self-promoters need love too,” so let’s give them a day. Speculating on why Sunday was forgotten in all the name schemes, you could go with “maybe we didn’t name Sunday because it’s sacred or something,” or “Oops, we overlooked that.” I’m going with the second option. And I agree. Let’s just call it Self-promotion Sunday. Or maybe Black Friday, Small Business Saturday and Cyber Monday are self-promotional enough. I’m not sure.