How does the Waitlist work?

When an item is sold out, your shopper will get the following 2 messages instead of a checkout link:

They will also get a comment autoreply so that others will see that it's sold out:

(you can turn off the comment autoreply in your WAITLIST tab)

Commenters who opted by clicking "Notify Me" show up in your WAITLIST tab:

And you'll be able to see the product that they're waitlisted for along with the variant options. In the case of the 1st user, their item came back in stock and so they were invoiced. In the case of the 2nd user, their item is still out of stock which is why the status is still 'Waitlisted' at the 'Back-in-stock date' field is empty. 

As long as the shopper clicks the "Notify Me" button, they will get messaged when the product becomes available again:

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 change in your Waitlist tab:

Once that hold time expires, she falls off the waitlist and we message the next person who was on the waitlist for that item. 

A couple additional details:

1) You'll want the 'One-Time Notification' enabled on your Facebook Page (see this article)

2) You'll want to keep the defaults: "Track quantity" checked and "Continue selling when out of stock" unchecked:

3) If the shopper who got the back-in-stock message clicks "No Thanks", they can no longer click on the Checkout button and the next person on the waitlist gets a back-in-stock message