Preorders and back in stock alerts work best as one system: alerts capture demand while a product is unavailable, and preorders keep selling once you have a ship date you can defend. One product can go live in a day, and the waitlist tells you what to reorder.
A sold out page is not a dead end. It is the cheapest demand research you will ever get, as long as you capture it.
Your bestseller sells out on a Tuesday. A shopper clicks an ad, reaches the product page, sees a gray Sold Out button, and leaves. You paid for that visit, and you have nothing to show for it: no email, no signal, no second chance.
Disclosure: this guide was produced in partnership with STOQ, the preorder and back in stock app I discuss. Sandesh Kulai, STOQ’s CEO, was a guest on the eCommerce Fastlane podcast. I have called out where a claim comes from STOQ and where it comes from Shopify or other sources, and I have noted where STOQ is one of several good options.
Every shopper who lands on an unavailable product and leaves is a demand signal you never recorded. On the eCommerce Fastlane podcast, Sandesh Kulai argued against hiding sold out products: the shopper came looking for that exact item, so keep the page live and capture the interest.
For a smaller brand, he said, the signup count can be worth more than the missed sale, because it shows what to reorder before you spend on the next purchase order. That is the part I would underline. A waitlist of 400 people on one variant is a purchase order argument you can make to a supplier, and a sold out badge is not.
You cannot promise inventory will always be available. You can decide what your store does at the moment it is not.
Use a notify me button when you do not know the restock date, and a preorder when you have a ship date you can defend. The two cover different moments in a product’s life, so most stores end up running both.
If you just sold out and your supplier has given you a written date, a preorder is usually worth it, because you keep the sale instead of keeping only an email address. If the date is a guess, start with the notify me button. Publishing a ship date you cannot back up creates refunds and angry emails, which costs more than the signups would have earned.
Back in stock emails are among the highest converting messages you can send because the shopper already asked for them, but published numbers vary widely, so measure your own baseline first. Omnisend’s 2025 ecommerce marketing report put back in stock emails at a 59.19% open rate and a 5.34% conversion rate, which it describes as proven winners among automations.
Other sources report higher figures, and some vendor roundups claim top stores reach well above 15%. Part of the gap is definition. Some numbers count orders per recipient and others count purchases per clicker, and many come from companies that sell the product being measured. Treat any single figure as a range, not a target, and compare yourself against your own first month of data.
One practical point holds regardless of the benchmark: speed matters because the shopper’s interest is fresh. Send the alert when inventory is actually available, not when someone remembers to do it.
Match the payment model to your lead time and price point: full payment for most products, a deposit when the price is high, and charge later when the timeline is uncertain.
Sandesh’s default is to collect full payment upfront for most categories. His reasoning is that customers who want the product will pay, and it keeps fulfillment and support as simple as an in stock order. He moves to a deposit when prices climb, such as furniture, where asking for $2,000 or $3,000 upfront breaks down. His example was a $100 to $500 deposit with the balance charged right before shipping.
What about a six week lead time? Six weeks is fine for full payment if the date is written, buffered, and shown on the product page, at checkout, and in the confirmation email. Move to a deposit if the price is high enough that buyers hesitate, and to charge later if the date could slip. A deposit also changes your checkout, as the next section explains.
Before you plan your first campaign, run through these constraints. Most stores will not hit all of them, but it is worth knowing which ones apply to yours.
Shopify’s rules change, so check the help page again right before launch. This is general information, not legal advice.
Notify in batches sized to the inventory you actually received, not to the size of your waitlist. Say 10,000 people joined your waitlist and 500 units arrive. If you email all 10,000 at once, most of them click through to a sold out page, which is a poor experience and a reason to stop trusting your alerts.
Sandesh recommends matching notifications to stock. As an illustration only, assume about 20% of notified subscribers buy. Then 500 units supports roughly 2,500 notifications, or a quarter of the list. Swap in your own conversion rate once you have one, send in waves, and keep the remaining signups for the next restock.
There is a second benefit. The people left on the list are your proof of demand for the next purchase order.
Put everything on the Shopify order itself, so everyone who touches it can see it. A preorder moves through your warehouse, shipping partner, and support inbox, and each needs to know it is different. Not every STOQ merchant uses a third party warehouse; some fulfill in house or ship with Shopify Shipping, and the same rule applies to all of them.
Sandesh’s advice is to use tags, the expected ship date on the line item, and internal notes. One brand used that data to build a custom widget in Gorgias, so agents could answer shipping questions without a native integration. Also hold preorder items so they do not ship with regular orders, and send a reminder before any deferred charge, since an unexpected charge is how chargebacks start.
AI helps most with the questions you would otherwise answer by opening a dashboard. STOQ lists four AI tools in the AI connectors section of its Integrations page. The descriptions below come from STOQ, and I have not tested each one myself.
Sandesh described a record label store that wired supplier street dates from product metafields into automated preorder campaigns, collection page updates, and a customer facing order status page. That is a larger build than most stores need on day one, but it shows where the tooling goes.
STOQ combines preorders with partial payment and inventory based limits, back in stock alerts by email and SMS, and analytics on demand and stockout trends in one app. STOQ reports 40,000+ active stores, 300K+ preorders processed, 13M+ alerts sent, and $155M+ in sales unlocked. Those figures are company reported, so read them that way.
It is not the only option. If you only need simple pay now preorders, you may not need an app at all, and other dedicated preorder apps exist at different price points. My preorder guide compares them by revenue stage. The practical test is whether you want alerts and preorders from one vendor, or the best tool for each job.
You do not need 30 days to start. One product can go live in a day, and that first live product teaches you more than any plan. Use the schedule below to scale the system once you know the flow works.
If you sell limited drops, my guide to running streetwear drops without dead stock shows the same logic applied to a short preorder window.
A preorder lets a customer buy a product before it is available, while a back in stock alert notifies a customer who asked to be told when a sold out product returns. Alerts capture interest when you have no date, and preorders capture the sale when you do. Most stores use both: a notify me button while the restock date is unknown, then a preorder button once the supplier confirms a date you can defend. The two also feed each other, because alert signups show how much demand a preorder is likely to see before you launch it.
Use a preorder if your supplier has given you a written restock date you can defend, because you keep the sale instead of keeping only an email address. Use a notify me button if the date is unknown or likely to move, since publishing a ship date you cannot back up creates refunds and angry emails. If you are unsure, start with the notify me button, watch how many people sign up, and switch to a preorder once the date is confirmed in writing.
Full payment works for a six week lead time when the ship date is firm and shown on the product page, at checkout, and in the confirmation email, and it keeps fulfillment and support simple. Choose a deposit if the price is high enough that buyers hesitate, and charge later if the date could slip. Whatever you pick, state the date and your cancellation policy up front, and remember that deposits and partial payments change which checkout buttons customers see.
Full payment fits most products and short to medium lead times, because customers who want the item will usually pay and the order behaves like any in stock order. Deposits fit higher prices and longer waits, such as furniture, where asking for the full amount upfront breaks down. Deposits and partial payments also change your checkout: in STOQ’s default setup they remove Shop Pay, Apple Pay, and Google Pay, so confirm your gateway and test the checkout before you plan one.
It depends on how the preorder is built. On purchase option preorders, which include deposits and partial payments, accelerated checkouts such as Shop Pay, Apple Pay, and Google Pay are not available, and local payment methods such as Klarna are not supported. Full payment preorders built without purchase options can keep accelerated checkout. Because apps build these listings differently, place a test order on your phone before launch to see exactly which payment buttons appear, and ask your app’s support if anything looks off.
Size the batch to your inventory and your expected conversion rate, not your full waitlist. If 500 units arrive and 10,000 people are waiting, emailing everyone sends most of them to a sold out page and teaches them to ignore your alerts. Send in waves, watch how quickly units sell, and keep the remaining signups for the next restock. Your own conversion rate from the first batch is a better guide than any published benchmark.
