Batou667 said:
Is there any kind of cultural significance to the event, i.e. the date or the name? Is it just coincidence that it's near Thanksgiving? Seems to me the shops would want to hike up the prices ahead of Christmas...
Okay here is an Honest answer to you're question rather than a bunch of people who don't understand basic economics, sneering at capitalism
The name "Black Friday" comes from an accounting term. If your books in the "Red" you're loosing money. If they are in the "Black" you're making money. The name comes from the fact that due to sales volume the Friday after US thanksgiving is the best time of year to get you're books in the black for the quarter.
Also if you think that it's the best time to hike prices than you don't understand one of the most important concepts of Capitalism. The Invisible Hand of Competition.
Black Friday is all about sales volume, getting people in stores to buy things, and sales are the best way to do that. If Alice is selling Widgets for £5 and Bob is selling them for £3 where do you shop. So stores offer the outright best sales of the year to entice shoppers to come to their stores rather than their competition. On Black Friday it is not uncommon to see things on sale for something like %80 off.