Updated July 2026. Based on 12.5 million back-in-stock emails, 4.3 million texts, and 173,000 WhatsApp messages sent July 2025 – June 2026. Open and click rates exclude bounced and rejected messages.

As e-commerce businesses strive to engage customers effectively, the performance of communication channels plays a crucial role. A full year of alert data shows where engagement really happens — and the ranking has changed since our original analysis.

Click Rates Across Different Notification Channels

Engagement by channel, July 2025 – June 2026. SMS click rate is measured on delivered messages; WhatsApp on successfully sent messages.

Email (63% open rate, 10.2% click rate)

Email remains the backbone: it rides along on 94% of all alerts, and because a back-in-stock email is requested mail, it opens at 63% — roughly three to four times a typical marketing campaign. About one in ten sent emails gets clicked.

• Reach: near-universal — every shopper who joins a waitlist can receive it.
• Role: the reliable base layer on every alert, at negligible cost.

SMS (31.7% click rate)

SMS turns the alert into an interruption shoppers actually welcome: 95% of texts are delivered, and nearly one in three delivered texts gets clicked — three times the email click rate.

• Immediacy: texts are read within minutes, which matters when half of all restock purchases happen within 2.3 hours of the alert.
• The adoption gap: SMS is enabled on only a third of alerts today. For most stores it is the single biggest untapped engagement upgrade available.

WhatsApp (~17% click rate)

The newest channel in the mix delivered about 173,000 alerts in its first full year, with roughly 17% of successfully sent messages clicked — landing between email and SMS, with plenty of room to grow as adoption spreads.

Push notifications, which led our 2024 comparison on click-through rate, have since faded to a fraction of a percent of alert volume as shopper preferences consolidated around email, SMS, and WhatsApp.

The bottom line. The 2026 ranking is clear: SMS drives the strongest engagement per message, WhatsApp is a promising middle lane, and email delivers unmatched reach. For businesses looking to maximize conversions, the multi-channel approach still wins: email as the base layer on every alert, SMS for speed with your highest-intent shoppers, and WhatsApp where your customers already spend their time.