SMS In-Stock Reminders with Twilio

We have all been in that place.  After scouring the web for that latest *must have* toy, and just as you are ready to add to growing debt you see the dreaded words – OUT OF STOCK.

At, such scenarios often resulted in young shredders contacting us via email, or even phone, asking when that super sick Landyachtz Evo deck was going to be available again.  Indeed something had to be done… the consumers want their stuff, so we brewed up a fancy new In-Stock reminder tool to satisfy the retail hunger.

New School and Old Skool

The feature is far from ground-breaking in the online retail world.  Many large e-tailers for years have been offering email-based reminders to shoppers to receive an alert when their desired item is back in stock.

But since a majority of the shoppers at The Longboard Store tend to be in their teens and early twenties, it seemed natural to offer a similar notification service, but via SMS. Additionally, SMS obviously has some major advantages over email-based communications (no-spam folders for the message to die in, immediate customer attention), so we decided to create a system that offered both email and sms notifications.

Sign Up Flow

When a product is out of stock, the user is presented with a call to action to be informed when the inventory is replenished. The design of the page is somewhat muted/grey, and this call to action is rather prominent:

The subsequent page provides the shopper two options for notification, SMS or email. Nothing too exciting here.

When a user chooses the text option, a confirmation sms is sent via the Twilio API (using twilio gem). The user can click the link in the text -or- enter the confirmation code on the web form to confirm their alert subscription.

Waiting Game

Now the consumer waits, iPhone in hand, credit card warming in pocket for that alert to arrive. A few other things that happen during this time though are the buyers can evaluate the number of alerts for given products/brands and adjust buying decisions accordingly.

When our receiving department checks in product, our Rails application determines if the product being checked in has any alert subscriptions, and enqueue’s a job to send notification to our customers that their product is now in stock. Simple. Beautiful.

All About Conversions

Indeed the project was fun to do, and having Twilio in my programmer toolkit made it all possible, but in the online retail space, it all comes down to conversions. So after letting the system run for the first quarter of the year, I decided to analyze the numbers.

To determine if a given alert signup resulted in a paid conversion on our sites, I simply cross-referenced the email/mobile signups from the alert table with those in the billing and shipping addresses on orders. Granted, this won’t catch every possible conversion, it is fairly accurate and accommodates not being able to track conversions with cookies across multiple devices.

  Email Alerts SMS Alerts
Alerts Sent 638 314
Unique Recipients 558 261
Conversions 75 33
Rate 11.75% 10.50%

These conversion rates are obviously well above our overall conversion rate for site visitors, and more than justify the added (albeit minor) expense of sending a text message over an email. I was personally quite surprised to see users signing up for multiple alerts. This makes me think in a future iteration we should allow users to manage all stock alerts via one unified tool – and thus reduce the burden (and cost) of confirming a subscription for each product.

The Future

Ultimately the beauty of this system is opening yet another way to keep a ongoing conversation alive with our customers. Being able to leverage systems like Twilio to connect with first-time and returning customers on mobile devices will continue to be a growing part of our strategy at The Longboard Store.