Email Marketing Benchmarks — May 2026

These are our May 2026 email marketing benchmarks — real data from 12 e-commerce brands and 9.5 million emails. The headline: campaigns took the revenue lead back from flows for the first time in months, on the back of a grilling-season surge at the portfolio's largest brand.

Across 12 e-commerce brands and 9.54 million emails in May, the portfolio generated $1,231,556 in email-attributed revenue — up 36% from April's $905K. Campaigns drove 59.0% of email revenue, reversing months of flow dominance, as seasonal campaign volume nearly doubled year-on-month. The portfolio flow multiplier landed at 20.1x, down from 24.5x in April as campaign RPR rose with the seasonal lift.

Flows still did the heavy lifting per recipient — $1.58 per recipient vs. campaigns' $0.08 — but the sheer volume of May campaign sends (9.22M recipients) tilted the revenue split. Email drove 30.0% of total store revenue across the portfolio, up from 28.2% in April.

May at a Glance

Portfolio: 12 brands · 9 verticals · $1,231,556 total email revenue · 9.54M recipients

Revenue split: Campaigns $726,086 (59.0%) · Flows $505,470 (41.0%)

Roster note: 12 active brands this month vs. 13 in April. One brand went dormant (zero sends in May) and one project-only account is excluded from the aggregate; the active roster is otherwise stable, with two smaller brands returning to the set.

Scorecard

vs. April: Total email revenue jumped 36% ($905K → $1.23M). Campaign revenue rose from $385K to $726K (+89%) while flow revenue slipped from $521K to $505K (-3%) — flipping the split from 42.5/57.5 to 59.0/41.0. Total recipients climbed from 7.50M to 9.54M (+27%), almost entirely on the campaign side (7.11M → 9.22M). Campaign open rate held at 43.42% (April: 44.11%); the flow open rate recovered sharply from 31.96% to 37.86% as last month's entry-criteria drags cleared. Campaign RPR improved from $0.05 to $0.08, flow RPR from $1.32 to $1.58. Email attribution rose from 28.2% to 30.0%.

vs. Industry Benchmarks

How does this portfolio compare to Klaviyo's published industry averages?

Campaign open rates sit 5+ points above industry. Click and conversion rates remain below industry averages — the audience-breadth tradeoff we've documented in February and March: the portfolio is weighted toward very large campaign audiences, which compress rate metrics. The flow open rate climbed back to 37.86% after April's dip, though it still trails the 48.57% industry flow benchmark.

Email attribution rose from 28.2% to 30.0%, holding above the ~27% industry benchmark for the third month running. Individual brand attribution ranges from 10.3% to 54.5%.

Klaviyo Benchmark Ratings (Campaigns)

Klaviyo benchmarks every account against similar-sized senders. Here's how our 12 brands stacked up on campaigns:

Flows distribution:

The familiar split holds: deliverability metrics (unsub, bounce, spam) skew Excellent or Good, while performance metrics (click rate, placed order rate, RPR) skew Poor — the audience-breadth math we explored in February's Spotlight on the click rate gap. Campaign RPR ratings improved this month: 4 of 12 brands now rate Good or Excellent as seasonal campaigns lifted per-recipient value. Flow click rate remains the weakest line — 7 of 12 brands rate Poor — a function of large, mixed-intent flow audiences.

The Flow Multiplier

We track what we call the Flow Multiplier — flow RPR divided by campaign RPR. For every dollar a campaign generates per recipient, how many dollars does a flow generate?

Range: 3.2x to 92.2x across all 12 brands. Median: 18.5x. Unlike April, every brand sent campaigns that converted, so there are no undefined multipliers this month. The portfolio aggregate (20.1x) is heavily influenced by the largest Scale-tier brand's recipient volume, whose own multiplier (32.4x) sits above the median.

Distribution: 5 brands at 30x or higher, 2 brands in the 10x–30x range, 4 brands in the 5x–10x range, and 1 brand under 5x. The highest multipliers belong to small-list, high-AOV brands (jewelry, beauty) where flows capture concentrated buying intent and campaigns reach a thin audience; the lowest belongs to a Food & Bev brand whose campaigns already convert strongly (campaign RPR over $1.00), compressing the ratio.

The Benchmarks

Here are the full email marketing benchmarks for May, broken down by revenue, engagement, deliverability, and the flow vs. campaign split.

Revenue

Total email-attributed revenue across the portfolio: $1,231,556.

Campaigns drove $726,086 (59.0%). Flows drove $505,470 (41.0%). The flow share fell from 57.5% in April to 41.0% in May — campaigns retook the lead for the first time since the winter. The driver is seasonal: the portfolio's largest brand (outdoor cooking) hit its grilling-season peak around Memorial Day, nearly doubling its campaign revenue month-over-month.

Campaigns went to 9.22M recipients. Flows went to 320K. Flows generated $1.58 per recipient vs. $0.08 for campaigns — a 20.1x portfolio-level gap, narrower than April's 24.5x because campaign per-recipient value rose with the seasonal lift.

Revenue by Brand (Email-Attributed)

The largest Scale-tier brand is, again, the gravity well of the portfolio — $731K of $1.23M in email revenue (59%), 5.04M of 9.54M recipients (53%). Its grilling-season campaign surge is what flipped the portfolio's campaign/flow split this month, and its weighting drives most of the aggregate rate calculations.

Notable individual brand stories this month: the B2B brand grew to the second-largest revenue driver ($102K) on strong campaign RPR ($0.29, Excellent) — a small, high-intent audience converting well. A small-list Beauty brand posted a $20.42 flow RPR, the highest single-channel efficiency in the portfolio, on under 3,000 flow recipients. A Food & Bev brand stood out for the opposite reason: its campaigns convert so well (campaign RPR $1.18) that its flow multiplier is the lowest in the set at 3.2x.

Engagement

Open Rate: Portfolio weighted average 43.24% (campaigns 43.42%, flows 37.86%). Range: 25.08%–54.08% for campaigns.

Campaign open rate held essentially flat from April's 44.11%. The flow open rate is the recovery story: it climbed from 31.96% in April to 37.86% in May as the entry-criteria issues that dragged two brands last month cleared. Five brands rate Good or Excellent on campaign open rate. As always, Apple's Mail Privacy Protection inflates these numbers; the signal is downstream.

Click Rate: Portfolio weighted average 0.47% (campaigns). Range: 0.24%–2.05%. Klaviyo's industry average is 1.29%.

Five of 12 brands rate Poor for campaign click rate — the larger-list senders where the audience math compresses rates, the same pattern from February's Spotlight on the click rate gap. The brands rating Good cluster among smaller-list senders (Food & Bev, Jewelry, Apparel).

Conversion Rate: Campaign average 0.03%. Flow average 0.54%. Flows convert at roughly 17x the rate of campaigns — consistent with April, even as campaigns carried more of the revenue this month on sheer volume.

Month-over-month: Engagement signals held or improved. Campaign click rate was steady (0.50% → 0.47%), flow click rate ticked up (2.08% → 2.28%), and flow conversion rate rose from 0.50% to 0.54%. The flow-side improvement reflects the open-rate recovery feeding through to downstream actions.

Deliverability

Unsubscribe Rate: 0.14% portfolio average, unchanged from April. Nine brands rate Good or Excellent on campaigns — 75% of the portfolio. One brand rates Poor (a small accessories brand at 0.40%). Healthy across the portfolio overall.

Bounce Rate: 0.34% portfolio average, down from April's 0.41%. Seven brands rate Good or Excellent for campaigns, and zero rate Poor. Flow bounce rates remain the watch-list item: five brands rate Poor on flows (one beauty brand at 3.83%, one accessories brand at 2.98%), concentrated rather than portfolio-wide.

Spam Complaint Rate: 0.008% portfolio average, effectively unchanged. Three brands rate Excellent for campaign spam rates. Most flagged rows carry elevated spam at low absolute thresholds, well below the 0.1% ISP danger line.

Deliverability remains the strongest section of the portfolio. The list hygiene work continues to show in stable bounce and unsub metrics across roster changes.

Flows vs. Campaigns

The core comparison:

After three straight months of flows out-earning campaigns in total revenue, May broke the streak — campaigns out-earned flows by $221K on a seasonal volume surge. The per-recipient efficiency gap held at 20.1x, narrower than April's 24.5x because campaign RPR climbed with the seasonal lift, not because flows weakened. Strip out the seasonal campaign spike and the underlying flow-vs-campaign relationship looks unchanged.

How to Read This Report

This report aggregates anonymized data from 12 e-commerce brands managed by our agency. Brands are identified by vertical and revenue tier:

• Emerging: <$25K/mo in email-attributed revenue
• Growth: $25K–$100K/mo
• Scale: $100K+/mo

Klaviyo Benchmark Ratings compare each brand's metrics against Klaviyo's industry percentiles:

• Excellent = 75th–100th percentile
• Good = 50th–75th percentile
• Fair = 25th–50th percentile
• Poor = 0–25th percentile

Weighted averages weight each brand by recipient count, so larger senders have proportionally more influence on portfolio metrics. The largest Scale-tier brand — with 5.04M of the portfolio's 9.54M recipients — carries the most weight.

Revenue figures are Klaviyo-attributed (last-touch email attribution with Klaviyo's default attribution window). These numbers represent revenue that Klaviyo attributes to email, not total store revenue.

This is the fifth edition of our monthly email marketing benchmarks report. Historical comparisons reference April 2026 data, March 2026 data, February 2026 data, and January 2026 data.

Frequently Asked Questions

Why did campaigns overtake flows in revenue this month?

Seasonality. The portfolio's largest brand sells outdoor-cooking equipment, and May — Memorial Day in particular — is its peak demand window. Its campaign revenue nearly doubled month-over-month, and because that single brand represents 59% of portfolio email revenue, its surge flipped the whole portfolio's campaign/flow split from 42.5/57.5 to 59.0/41.0. Per recipient, flows are still far more efficient ($1.58 vs. $0.08); campaigns simply sent to 29x more people this month.

What is the flow multiplier and why did it drop to 20.1x?

Flow multiplier is flow RPR divided by campaign RPR — how many dollars a flow earns per recipient for every dollar a campaign earns per recipient. It dropped from 24.5x in April to 20.1x in May, but not because flows weakened. Campaign RPR rose from $0.05 to $0.08 on the seasonal lift, which compresses the ratio. The May per-brand range was 3.2x to 92.2x, with a median of 18.5x.

Why is click rate so far below the industry average?

Audience size. Click rate has a mathematical relationship with how many people you send to — the larger the audience, the lower the rate. Klaviyo's industry average (1.29%) is computed across senders of all sizes; our portfolio is weighted toward larger lists where rate metrics naturally compress. Total clicks and total revenue are the metrics that actually matter at scale — we explored this fully in February's Spotlight.

Are the rate metrics seasonally adjusted?

No. We publish monthly raw figures so month-over-month comparisons are transparent. May is a 31-day month that includes Memorial Day, a major promotional moment for outdoor, grilling, and apparel brands. That seasonality is exactly why campaign revenue and volume spiked this month — we leave it in rather than smoothing it out.

How does this benchmark compare to my own brand?

Compare your own metrics against the table in this post and against your Klaviyo benchmark percentiles. The most useful single comparison is your flow multiplier — flow RPR divided by campaign RPR. The May portfolio range was 3.2x to 92.2x, with a median of 18.5x. If you want a deeper read tailored to your brand, get in touch.