How does the waitlist work?
After your shopper comments for an item that's sold out, they'll get this message if this is the first time they've been added to a waitlist:
If they've already been added to a waitlist before and clicked "Get messages" in the past, they will just get automatically added to the waitlist and get the following message:
And once the product becomes available for them to buy, they'll get a message with their invoice:
The "Buy Now" button goes to a draft order that has the note that this was a "Soldlive invoice (from waitlist)"
The first customer(s) that got the back-in-stock message has a certain time to make the purchase. This time is determined by your back-in-stock hold time which you can customize in your Waitlist tab:
Once that hold time expires, the next person who was on the waitlist for that item gets messaged
Some additional details
1) You'll want to keep the defaults: "Track quantity" checked and "Continue selling when out of stock" unchecked: