How to be sure about the message delivery?

WhatsApp™ is an extremely widespread messaging service, but it doesn't reach the 100% of the users. Moreover there is the possibility that some users do not result "subscribed" at your service.

The only way out to be really sure about the message delivery is to use the SMS channel ("SMS fall back").

This SMS fall back system forward WhatsApp" messages to our SMS gateway, ensuring the delivery of your communications to the users of your service, by a cost-optimized procedure!