Also known as: CTOR, Click-to-Open Ratio
Click-to-Open Rate (CTOR) is the percentage of people who clicked a link inside an email out of the people who actually opened it. It isolates how compelling the email's content is, separate from how many people opened it in the first place.
The distinction matters. Open rate measures your subject line and sender reputation; click-through rate (CTR) measures clicks against everyone you sent to. CTOR sits between them, measuring clicks against openers only — so it answers a sharper question: once someone reads the email, does the content and call to action actually move them?
For an IB or affiliate, CTOR is the truest read on creative quality. A weak subject line can drag CTR down even when the email body is excellent; CTOR strips that away and shows whether your offer, copy, and affiliate link are persuading engaged readers. Typical email CTOR benchmarks run roughly 10–15%, though finance and high-intent audiences vary widely.
As a concrete example, an affiliate sends a promotion to 5,000 subscribers. If 1,000 open it and 150 click the broker signup link, CTOR is 15% — even though CTR against the full list is only 3%. Watching CTOR tells you the body converted well and the real bottleneck was the subject line holding opens down.
CTOR is computed from two figures your email platform already tracks: unique clicks and unique opens. Divide unique clicks by unique opens and multiply by 100. Using unique counts (one per person) rather than totals avoids inflating the number when one reader clicks several times.
Because the denominator is openers rather than everyone sent, CTOR neutralizes list size and subject-line strength. Two emails with very different open rates can be compared fairly on how well their bodies converted. That makes CTOR the metric to watch when you A/B test body copy, CTA wording, button placement, or offer framing.
One caveat: privacy features like Apple Mail Privacy Protection auto-open images and can inflate reported opens, which distorts open-based metrics including CTOR. Treat CTOR as a directional creative signal and pair it with click-to-delivered and downstream conversion rather than reading it in isolation.
Get the number of distinct recipients who opened the specific email from your email platform's report.
Get the number of distinct recipients who clicked any tracked link inside that same email.
Divide unique clicks by unique opens, then multiply by 100 to express CTOR as a percentage.
Benchmark the result against your own past campaigns and the ~10–15% general range, not just industry averages.
Change CTA wording, button placement, or offer framing and re-measure CTOR to see which body converts opens best.
Why it matters for partnership: CTOR isolates whether your email content and affiliate links actually persuade engaged readers, separate from subject-line performance. Affiliates use it to test copy and CTA placement, so they optimize the exact lever that turns opens into broker signups.
An affiliate promoting Pepperstone sends a market-update email to 8,000 subscribers. It gets 1,600 opens and 240 clicks on the signup link — a 15% CTOR against a 3% list-wide CTR. When they move the CTA button above the fold in the next send, CTOR rises to 19%, signaling the body change, not the subject line, drove the extra clicks.
| Metric | Denominator | What it measures |
|---|---|---|
| Open rate | Emails delivered | Subject line + sender reputation |
| Click-through rate (CTR) | Emails delivered | Overall clicks per send |
| Click-to-open rate (CTOR) | Emails opened | Content + CTA quality among readers |
When CTOR is low but opens are high, your subject line is over-promising or your CTA is buried — deliver on the subject's promise and lift the button above the fold before touching the subject line.
Burying the affiliate link at the bottom of a long email, producing strong open rates but a weak CTOR because engaged readers never reach the call to action.
A general benchmark is around 10–15%, but it varies by industry and audience intent. Compare against your own past campaigns rather than a single universal target.
CTR divides clicks by everyone the email was delivered to. CTOR divides clicks by only those who opened it, so it measures content quality independent of subject-line strength.
Usually the subject line over-promised, the offer is weak, or the CTA is buried. Align the body with the subject's promise and make the call to action prominent.
Yes. It auto-loads images and can register opens that never happened, inflating the denominator and understating CTOR. Pair CTOR with click and conversion metrics.
Match the body to the subject line, keep the CTA above the fold, use one clear primary action, and A/B test button wording and placement while holding the subject line constant.
Use unique counts — one per recipient. Total clicks inflate the ratio when a single reader clicks repeatedly, giving a misleading view of engagement.