Definition
In messaging, click-through rate (CTR) is the share of delivered messages whose link or button was clicked, calculated as unique clicks divided by delivered messages. It measures how well a message prompts action.
CTR is measured with tracked links (a redirect or short link that records clicks) or button events on WhatsApp and RCS. Use unique clicks per recipient to avoid one person's repeated clicks inflating the result, and divide by delivered rather than sent messages.
Automated clicks distort CTR. Link previews in messaging apps, security scanners and some operators' content filters may fetch URLs without a human tapping them. Filter known bots and look at downstream behaviour (time on page, conversions) to judge real engagement.
Drivers of CTR include a clear single call to action, a recognisable brand and short trustworthy domain (unknown shortened URLs look like phishing), personalisation, and timing. On WhatsApp and RCS, buttons and rich cards usually make the action easier than a plain URL.
CTR is an intermediate metric. Use UTM parameters on links so clicks can be followed through to sign-ups or sales in your analytics tool.
Example
9,420 delivered, 640 unique clicks → CTR 6.8%