They don’t send out notifications for things like WTF deals but if you subscribe to the Woot newsletter, check the forums, or visit the Woot web site, you can find out when stuff like this is scheduled to go down.
(Please note: I don’t work for Woot, I just volunteer to help out here on the forums.)
The Prime truck pulled up and I figured it was for across the street bc I haven’t ordered anything from Amazon recently. He came to the door and I still had no idea what it was.