Blossom Answers · straight answers on Klaviyo, email and retention
Barely. In Blossom Ecom's study of 4,029 shipped email campaigns across 10 DTC brands, open rate was almost uncorrelated with revenue per recipient — a median within-brand rank correlation of +0.11 (range −0.16 to +0.30 across 9 brands with n≥30) — against +0.35 for click rate. On some brands, higher-opening campaigns earned *less* per recipient. Click rate predicted revenue on every brand in the study. If your email program is graded on opens, it is being graded on a number that is close to noise.
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9 brands qualified (n ≥ 30 campaigns each, all three metrics present); 4,023 campaigns in the correlation analysis.
Three things worth noticing:
1. The open-rate range crosses zero. On at least one brand, campaigns that opened better earned less per recipient. No brand showed that inversion for click rate, its correlation with revenue stayed positive on every brand measured. 2. This is a within-brand result. We never pooled brands into one big correlation, a pooled number would let one large account's scale masquerade as a cross-brand pattern. Each brand was measured against itself; the reported figure is the median across brands. 3. The dashboards are pointed at the weaker number. Most ESP A/B tests crown the open-rate winner by default, and Apple Mail Privacy Protection has been inflating opens mechanically since 2021. In this dataset, an open-rate verdict is close to a coin flip on revenue.
deliverability diagnostic, not a performance verdict.
winner. In this dataset click rate carried roughly three times open rate's correlation with revenue per recipient.
pattern. A single campaign's split rarely resolves anything below a very large effect.
mechanically scans output for client identities and refuses to emit if any appears.
settings. Attributed revenue is not incremental revenue, and we say so. Campaign revenue only, flow revenue is not in this dataset.
Two compounding reasons. Opens are inflated mechanically, Apple Mail Privacy Protection auto-fires open pixels regardless of whether a human read the email, and an open is an attention event, not an intent event. A click is the reader acting on the offer; that is why its correlation with revenue per recipient held positive on every brand we measured.
No. Subject lines decide whether the email gets seen at all. What the data says is that the open rate a subject line produces is a poor verdict on the revenue the campaign produces, grade the test on clicks and revenue per recipient instead, and pool many tests before trusting a pattern.
Blossom Ecom's own client accounts, 10 DTC ecommerce brands running full-service Klaviyo programs. No brand is named and no per-brand figure is published; every result is computed within brand and reported as a cross-brand median with its range.
The findings sheet is free to cite with attribution. For the dataset and the exact filter definitions, email andres@blossomecom.com, research collaborations and editorial fact-checks welcome.
Yes, the study is a standing pipeline, and this hub adds findings as they clear the replication bar (a finding must hold within brand across most of the roster before it publishes).
Blossom Ecom is an email & SMS retention agency for DTC ecommerce brands. We run full-service Klaviyo programs, lifecycle flows, campaign calendars, segmentation, deliverability and A/B testing, with a published price, a written performance guarantee, and a stated cap on how many brands we take each month. → See pricing and the guarantee · Case studies
> Blossom Ecom, "The Blossom Campaign Study, Finding #1: open rate vs. revenue" (v1.0, August > 2026). 4,029 shipped email campaigns, 10 DTC brands, Nov 2019 – Aug 2026. > blossomecom.com/research/campaign-study/open-rate-and-revenue/
Citation with attribution is welcome, no permission needed. For the underlying dataset, method definitions, or the analysis script's filter logic: andres@blossomecom.com.
September 11, 2026
