What an SMS Actually Costs

An SMS looks like the cheapest thing in the world. A few kobo, a hundred and sixty characters, gone. That apparent cheapness is exactly what makes it so easy to do badly.

When a school decides to reach parents by text, the conversation usually starts and ends with the per-message price. But the price of one message is the least interesting number. The cost that matters is the cost of reliably reaching every parent, every time, in a way the school can afford to keep doing for years. Once you frame it that way, SMS turns out to be a genuinely demanding engineering problem wearing a humble disguise.

The hidden line items

Past the headline price, the real bill includes things nobody quotes you:

• Failed and silently dropped messages. A message you paid for that never arrived is worse than no message — the school believes the parent was told. Knowing delivery actually happened costs effort, and not knowing costs trust.
• Bad numbers. Real parent lists are full of old, mistyped, and duplicated numbers. Every send against a dead number is money spent reaching no one. Hygiene of the list is a recurring cost, not a one-time clean.
• Length. One careless message that runs to 200 characters is billed as two. At a few thousand recipients, sloppy wording quietly doubles a school's bill. Concision is a budget line.
• Timing and retries. Sending ten thousand messages well — paced, retried on failure, not flagged as spam — is very different from firing them all at once and hoping.

Why it's still the right channel

With all that, why not just use an app and push notifications? Because the parent you most need to reach is the one least likely to have your app installed, updated, and open. SMS asks nothing of them: no download, no account, no data plan, no smartphone even. It lands on the cheapest phone in the most remote place. For a school that genuinely means all parents — not the connected ones — that universality is worth more than any feature an app could offer.

So the craft becomes: how do you get the reach of the lowest-common-denominator channel without paying the lazy version's hidden tax? You write tight. You clean the list. You confirm delivery. You pace the send. You measure what actually arrived, not what you sent.

The real economy

Done well, the true cost of an SMS is low — not because the message is cheap, but because every naira buys a message that actually arrives and actually gets read. Done badly, the same channel is a slow leak: money spent texting dead numbers, parents who never got the notice, and a school that slowly stops trusting the system and goes back to phone calls and paper.

The cheapest channel is the one that reaches everyone you meant to reach. Everything else is just postage.