What is cost per message?

Cost per message is what one send costs: the campaign's platform and carrier cost divided by its sends. For email it is small and flat; for SMS it is the dominant economic fact, driven by carrier rates per segment and by how many segments each message needs. It is the cost half of messaging unit economics, paired with revenue and net margin per message.

Formula

cost per message = send cost ÷ sends

Worked example

An SMS campaign sends 10,000 messages at 2 segments each, at €0.045 per segment: €900, or €0.09 per message. Trimming the copy to one segment halves that to €0.045. With €0.30 of attributed margin per message, the trim moves net margin per message from €0.21 to €0.255 — a fifth more profit from a copy edit.

How Saldo Metrics computes it

fact_messaging_performance stores each row's send cost dual-stored — the as-billed amount in its original currency plus the EUR conversion at the ECB rate (send_cost_base). v_messaging_performance divides send_cost_base by sends per campaign or flow-message row, and the same cost feeds net_margin_base (attributed margin minus send cost) and net_margin_per_message beside it. Email rows may carry no cost at all when the platform bills flat; the division then shows nothing rather than a made-up zero.

Why it matters

Messaging looks free next to paid ads, and for email that is roughly true — which is exactly why SMS needs this column. An SMS program judged on revenue alone can grow itself into thin or negative net margin as segments and volume climb. Cost per message is where that shows first, and it is the number to check before scaling any SMS flow.

Common mistakes

• Treating messaging as costless in channel comparisons. The messaging-vs-paid comparison uses net margin (after send cost) for messaging precisely so the comparison is fair.
• Watching cost per message while ignoring segments per send. For SMS the ratio of segments to sends is the lever; cost per message just reports it in euros.
• Averaging across media. Email and SMS costs differ by orders of magnitude; a blended figure over both is meaningless. Compare within a medium.

Where you see this in the app

Marketing → Messaging, as the cost-per-message column of the campaign table.