---
title: "Email & SMS: From Channel Cost to Profit Contribution"
description: "ESP and SMS fees are small until you add discounts and list fatigue. Measure profit contribution, not opens."
date: 2026-08-31
updated: 2026-08-31
author: CostRadar Editorial
tags: [email, sms, profit]
heroKeyword: email SMS profit contribution
draft: false
---

Owned channels look free and are not. Platform fees, discount codes, deliverability work, and unsubscribes all hit true net profit—flows deserve ranking by contribution, not open rate.

## The "free channel" myth

ESP and SMS platform fees scale with list size and send volume, and every discount code sent to a list erodes margin on each redemption—none of that shows up in an open-rate report.

## Costs that compound over time

Deliverability consulting, list cleaning, unsubscribe and spam-complaint management, and the opportunity cost of fatigue-driven unsubscribes reducing future revenue from the list.

## Measuring by contribution, not opens

Rank flows and campaigns by profit contribution per send, factoring in discount cost explicitly, rather than by open or click rate alone.

## FAQ

**Do discount codes in email always hurt profit?**

Not if they are targeted—win-back flows, for example—rather than blanket sitewide discounts. Model the incremental margin, not just the incremental revenue.

**Should SMS get the same profit scrutiny as email?**

Yes, and often more—per-message SMS platform fees make low-margin blasts costlier per contact than the equivalent email send.

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CostRadar tracks ESP and SMS platform fees alongside discount cost, so owned channels get ranked by profit contribution instead of engagement metrics alone.