Read every metric as numerator, denominator, and who counted it
Before comparing a number across platforms or against an industry benchmark, ask three questions. What is counted on top? What is it divided by: sent, delivered, or opened? Is each person counted once, unique, or every time, total? Then ask whether machines were filtered out.
Kit gives its click formulas plainly: click-to-delivery rate is subscribers who clicked divided by subscribers who received the email, and click-to-open rate is subscribers who clicked divided by subscribers who opened. [1] beehiiv divides almost everything by emails delivered. [2] MailerLite describes most percentages in words and defines deliveries as sent emails excluding hard bounces. [3]
Metric formulas and how each platform counts
The formula column is the standard definition. The platform columns quote or paraphrase each vendor's help article. A dash means the vendor's article does not define that metric.
| Metric | Formula | beehiiv | Kit | MailerLite |
|---|---|---|---|---|
| Delivered | Sent minus bounced | Accepted at the mailbox provider's gateway; not a promise of inbox placement [4] | — | Deliveries are sent emails excluding hard bounces [3] |
| Open rate | Unique openers / delivered | Opens / delivered; called a directional metric at best [2] | Listed on the dashboard without a formula [1] | Subscribers who opened, as a number and percentage [3] |
| Click rate (CTR) | Unique clickers / delivered | Published as Click-To-Open Rate: clickers / delivered [2] | Click-to-delivery rate: clickers / recipients [1] | Subscribers who clicked at least one link [3] |
| Click-to-open rate (CTOR) | Unique clickers / unique openers | Glossary defines it this way; the Posts Report uses delivered instead [5] | Clickers / openers [1] | Openers who clicked a link [3] |
| Unique vs total clicks | Unique counts each person once | Unique Clicks counted once per subscriber [2] | Clicked counts recipients who clicked at least one link [1] | Link report shows both total and unique per link [3] |
| Verified clicks | Clicks after bot filtering | Filters on IP, user agent and click patterns [6] | — | Automated clicks are recorded as subscriber activity [7] |
| Unsubscribe rate | Unsubscribes / delivered | Unsubscribes / delivered [2] | Listed without a formula [1] | Subscribers who clicked the unsubscribe link [3] |
| Spam complaint rate | Complaints / delivered | Spam reports / delivered [2] | — | Subscribers who reported the campaign [3] |
| Hard and soft bounce rate | Bounces / sent | — | Bounce rate listed in the overview [1] | Hard and soft bounces shown separately [3] |
Money and audience metrics
CPM is what an advertiser pays per thousand impressions, and CPC is what an advertiser pays each time a reader clicks a sponsored link. [5] Revenue per send at a CPM rate is impressions divided by 1,000, times the rate. Agree in writing what counts as an impression. If it means email opens, Apple's background loading inflates the count, which favors the publisher and costs the advertiser.
Churn is not defined in the vendor glossaries cited here, so use the standard arithmetic: subscribers lost in a period divided by subscribers at the start of that period. Track free and paid churn separately. Free churn mixes unsubscribes, bounces and complaint suppressions. Paid churn is cancellations, which matter far more for revenue.
| Metric | Formula | Example |
|---|---|---|
| CPM revenue | (impressions / 1,000) x CPM | 4,410 opens at a $25 CPM = $110.25 |
| CPC revenue | Clicks x CPC | 150 sponsor clicks at $0.80 = $120.00 |
| Monthly churn | Lost in month / count at start of month | 18 cancellations from 400 paid = 4.5% |
| Net growth | New minus lost, over start count | 300 new minus 90 lost on 9,800 = 2.1% |
| Revenue per subscriber | Revenue in period / average subscribers | $1,200 on 9,800 = about $0.12 |
What Apple Mail Privacy Protection distorts
Apple says Mail Privacy Protection downloads remote content privately in the background by default, regardless of whether the person engages with the email, and hides the reader's IP address. [8] Open tracking works by loading an invisible pixel, so a background download looks like an open. [4]
The distortion spreads to anything built on opens: open rate, click-to-open rate (its denominator grows, so it falls), resend-to-non-openers, open-based segments and engagement scores, and open-based location reports. beehiiv says it filters non-human interactions such as bot activity and prefetching, and also lists Mail Privacy Protection among reasons a pixel may not load at all, so the effect can run in either direction. [9]
Clicks are not fired by background image loading, but security systems sometimes click links to check them. MailerLite says these show up as multiple opens or clicks within seconds and are recorded under the subscriber. [7] beehiiv's Verified Clicks flags patterns such as several clicks seconds after an open. [6]
- Inflated: open rate, opens-based engagement, opens by location, CPM deals priced on opens.
- Deflated: click-to-open rate, because the opener count is padded.
- Unreliable for targeting: resend to non-openers and inactive-subscriber rules that look only at opens.
- Mostly unaffected: verified clicks, replies, purchases, unsubscribes, complaints.
Worked example: one send, three ways to report it
Assumptions for a constructed example: 10,000 sent, 80 hard bounces, 120 soft bounces, 4,410 unique opens of which an estimated 1,800 are background loads, 392 raw unique clickers, 343 clickers after bot filtering, 29 unsubscribes and 2 spam complaints.
Delivered under the strict definition is 10,000 minus 200 bounces, or 9,800. Under MailerLite's wording, deliveries exclude hard bounces only, giving 9,920. That one choice moves the open rate from 45.0% to 44.5% before anything else changes.
Strip the estimated 1,800 background loads and human opens fall to 2,610, an open rate of 26.6%. Click-to-open rate then jumps from 8.9% to 15.0%. The clicks did not change. Only the denominator did.
| Metric | Calculation | Result |
|---|---|---|
| Open rate (strict delivered) | 4,410 / 9,800 | 45.0% |
| Open rate (sent minus hard bounces) | 4,410 / 9,920 | 44.5% |
| Open rate without background loads | 2,610 / 9,800 | 26.6% |
| Click rate, raw | 392 / 9,800 | 4.0% |
| Click rate, bot-filtered | 343 / 9,800 | 3.5% |
| CTOR, raw opens | 392 / 4,410 | 8.9% |
| CTOR, without background loads | 392 / 2,610 | 15.0% |
| beehiiv-style Click-To-Open Rate | 392 / 9,800 | 4.0% |
| Unsubscribe rate | 29 / 9,800 | 0.30% |
| Complaint rate | 2 / 9,800 | 0.02% |
Checklist before you compare numbers
Use this when reading a sponsor media kit, a benchmark report, or your own dashboard after switching platforms.
- Confirm the denominator: sent, delivered, or opened.
- Confirm unique or total. Total clicks include repeat clicks by the same person, so they are never lower than unique clicks.
- Ask whether clicks are bot-filtered and by what method.
- Treat open rate as a trend line on one platform, not a number to compare across platforms.
- Remember beehiiv's Posts Report covers posts you send or schedule; posts sent through automations are not included. [2]
- Watch complaints against Google's guidance: below 0.10% in Postmaster Tools and never 0.30% or higher. [10]
- Price sponsorships on clicks or on a fixed fee when your audience reads mostly in Apple Mail.
Questions before you decide
Does Apple Mail Privacy Protection affect click rates?
Not directly. Apple says Mail downloads remote content in the background whether or not you engage with the email, which fires open pixels. Clicks need a link request. Security scanners that click links are a separate problem, which beehiiv addresses with Verified Clicks.
Does MailerLite filter bot clicks?
Its help article says some servers and security systems click links to check them, and that MailerLite records these automated clicks as subscriber activity. It suggests spotting them by multiple opens or clicks within seconds.
Why is beehiiv's click-to-open rate lower than other platforms' CTOR?
beehiiv's Posts Report defines Click-To-Open Rate as subscribers who clicked at least one link divided by emails delivered. Kit, MailerLite and beehiiv's own glossary define CTOR as clickers out of openers, which gives a larger number.
Is Google's 0.10% spam rate measured per campaign?
Google refers to the spam rate reported in Postmaster Tools and says to keep it below 0.10% and never reach 0.30%. A single campaign's complaint percentage in your platform is a useful early warning, but it is not the same measurement.
Sources & verification
Product details and prices can change. Check the linked provider before buying.
- Kit Help: The Kit Broadcasts dashboard Accessed 30 Oct 2026
- beehiiv Support: Understanding your Posts Report Accessed 30 Oct 2026
- MailerLite Help: How to analyze and export reports Accessed 30 Oct 2026
- beehiiv Support: The email journey, key delivery events at beehiiv Accessed 30 Oct 2026
- beehiiv: Newsletter glossary Accessed 30 Oct 2026
- beehiiv Support: Understanding Verified Clicks Accessed 30 Oct 2026
- MailerLite Help: Why does my campaign show unusually high opens or clicks? Accessed 30 Oct 2026
- Apple: Mail Privacy Protection and privacy Accessed 30 Oct 2026
- beehiiv Support: Understanding open rate declines Accessed 30 Oct 2026
- Google: Email sender guidelines Accessed 30 Oct 2026
Sources link directly to providers. Product buttons may use separately labeled affiliate links. Read our disclosure.