A broadcast on the WhatsApp Business Platform uses an approved message template. Recipients do not see each other, and a reply opens a normal one-to-one conversation with the business.
Three limits apply. The messaging limit caps how many unique recipients a business portfolio can reach in a moving 24-hour period, starting at 250 for a new portfolio. Each delivered message is charged at the marketing rate of the recipient's country. And WhatsApp may hold back marketing templates for people who already receive many of them; it does not currently deliver marketing templates to United States phone numbers at all.
Effective broadcasting depends on list quality and segmentation. Sending relevant messages to engaged, opted-in contacts keeps the quality rating high and avoids the blocks that come from over-messaging.
On Shopify, Kanal sends WhatsApp broadcasts to opted-in customer segments built from store data.