Hi Ulrike!
your post made me laugh, what you think of when people say black friday and cyber monday are hilarious!
Black Friday is basically the biggest shopping day of the year in the states. Always the Friday following Thanksgiving, stores have crazy deals/bargains/low prices/sales and people go crazy! Lots of big chain and department stores even open their doors at midnight, 1, 2, 3, 4 am! And there are plenty of people waiting.. sometimes huge lines form outside the doors. Sales are just everywhere! I used to work retail and Black Friday is very much geared towards items that you can usually find easily, but the prices are reduced so everyone wants to get it on one day ie. electronics, computers, sports equipment, beauty gift boxes, and such.
Cyber Monday on the other hand is the same idea, only online. Black Friday people are usually out and about, so I'm not sure about internet traffic on that day, but on the following Monday, get ready! Everyone all over the internet is looking for deals/sales and free shipping. If you haven't already, and you plan on it, I would definitely add something like "cyber monday sales" in your tags with different variation of each product. If you have any sales, coupons, or deals, I would definitely market those and get the word out!
It's a very crazy weekend after Thanksgiving, but people get so crazy around the holidays! It's my first Black Friday and cyber Monday on etsy, so fingers crossed! I have no idea how this will pan out. But I hope you understand now, the market isn't crashing ;) and best of luck to you!
Tessa