Likewise, I can anecdotally add that in implementing various analytics packages for a variety of ecom sites, I've noticed that Cyber Monday is a -very- notable

Likewise, I can anecdotally add that in implementing various analytics packages for a variety of ecom sites, I've noticed that Cyber Monday is a -very- notable bump in traffic that stands out clearly when you're looking over traffic from the past couple of years. Was it like this before "Cyber Monday" was marketed as such? I have no idea, but there is definitely data out there to back this up. If you're an online retailer and you're not seeing a spike in traffic that day, you're doing something wrong.