https://www.youtube.com/watch?v=Giub2JmpXhA

Go there, turn on volume. They alert you with audio, then post a link in the chat whenever a product they are watching comes instock.

Also, if you join their discord server, http://restockwatch.com/discord and Then scroll down to the 4090 channel, They are usually a few seconds faster at posting the link in Discord, as the YT video is about 30 seconds behind.

I was only on the YT channel and Discord for 2 days, before I got myself a Zotac 4090. It wasn't my preferred card, but it is a 4090.

EDIT: I should say, I got lucky. There are people that were sitting in the YT chat for weeks, trying to get a card. But they didn't use the discord channel, so I suspect that's why they could never get a card to go through the cart. So me getting a card in 2 days seems to be a bit of a rare / lucky case. OH and FYI, if you try this, Make sure you are already logged into the sites ( Amazon, Newegg, BestBuy etc..) and have your address and payment info already stored in their store. If you have to log-in whenever you try to buy one, or have to enter your CC info...you will NEVER get one.