What is a pre-order?
A pre-order lets a shopper buy a product before it is in stock to ship. The store takes the order now and commits to fulfill it on a stated date, when the run arrives or the launch goes live. It turns a "coming soon" page into a working buy button, so demand is captured at the moment of interest.
Example
Say you are launching a jacket and the next batch lands in three weeks. Without pre-orders, the product page shows "Sold out" and 60 interested shoppers leave empty-handed. A pre-order button reading "Ships March 3" lets those 60 buy today. If even 30 commit at $90, that is $2,700 booked before a single jacket reaches your shelf. On the day the pre-order opens, a product launch email tells your subscribers it's live.
The orders also size your next purchase order. Thirty pre-sold tells you the batch should be bigger than you guessed, with some safety stock on top so a busy launch week doesn't sell you out again.
On Shopify stores
On a Shopify store, a pre-order swaps the disabled "Sold out" button for an active one labeled with a ship date. Behind it, the order is tagged for delayed fulfillment and held until stock lands. The honest part is the date: a pre-order that ships late, or hides when it ships, costs more trust than the sale was worth. Set the expectation on the button and on the confirmation. If the date slips anyway, tell buyers before they ask, with a shipping delay email template.
Pre-orders with Sledge
Sledge Pre-order turns a sold-out or upcoming product into a working buy button with a ship date, so interest converts the day it arrives instead of leaking away. Shoppers pay in full now, or put down a deposit and settle the balance later where the payment gateway and region allow it.