Start with the message purpose
An appointment reminder, service update and promotion are different use cases. Identify the audience, urgency and expected next step. The channel should fit the customer relationship and the information being sent.
Understand the operational difference
SMS can deliver short text without requiring a particular chat app. WhatsApp can support richer conversations but needs appropriate business setup and adherence to provider rules. Neither channel makes an undocumented contact list appropriate to use.
Plan replies and measurement
Who answers questions, handles opt-outs and updates contact records? Delivery is not the same as reading or purchase. Tagged links and consistent enquiry records can help, but the reporting should acknowledge what cannot be observed.
Compare the full cost
Review sending charges, segment length, platform fees, setup and staffing. Current pricing and policies must be confirmed with the provider. Choose a small, relevant campaign and a clear follow-up process before increasing volume.
