A marketer sent the first mass email - to 400 people. It booked his company $13 million in sales. People have been declaring email dead almost ever since.
People keep saying email is dead. The numbers say the opposite. Here they are.
Start with the population. Around 4.5 billion people use email - roughly half of everyone alive. Each dot here is about 10 million people.
And it isn't a young-vs-old story: 70%+ of every age group uses email monthly.
| Email users worldwide | 4.5B |
| Share of world population | ~50% |
| Use email monthly (all ages) | 70%+ |
That user base sends a torrent: 361.6 billion emails every day - and it climbs about 4% every year.
| Today | 361.6B / day |
| Spam share | ~45% (~162B) |
You probably think you ignore marketing email. The behavior data disagrees - and it starts before you're even out of bed.
11% check email the instant they wake. 19% within 30 minutes. 78% before they start work.
| Check email daily | 88% |
| Check 3–5× per day | 39% |
| Check before work | 78% |
| Check within 30 min of waking | 19% |
| Check immediately on waking | 11% |
Follow 100 sent emails through the gauntlet. Watch the cohort shrink at every gate. We start with all 100, just sent.
| Sent | 100 |
| Delivered | 81 |
| Opened | 32 |
| Clicked | 2 |
| Converted | 1 |
Deliverability runs about 81%. Nearly one in five emails dies in spam folders and filters before a human ever sees it. 81 left.
Just under a third get opened - 32%. Of those, 15% get under 2 seconds, 23.5% get 2–8 seconds, and 61% get a real 8+ seconds. ~32 left.
Click-through lands at 2%. Out of the original hundred, just two act. That sounds like failure - until you see what it costs.
Email doesn't win because everyone reads it. It wins because enough people give it 8 seconds at almost no cost - and the math still prints money. Here's the money.
That's the number that ends the argument. Email returns $36 for every $1 spent - $45 in retail and ecommerce. A 3,600% return.
| Average ROI | $36 : $1 |
| Retail / ecommerce | $45 : $1 |
| As a percentage | ~3,600% |
Social. Paid. Direct mail. Each was the email-killer of its moment. Each came in lower. Email stays the best-ROI channel for B2C, and ties social as the #2 most-used channel (40% each).
73% of B2B marketers say email is their single most effective prospecting channel.
| Email (relative ROI index) | 28.5 |
| Direct mail | 7 |
| Most-used channel (email ≈ social) | 40% each |
| B2B: email = most effective | 73% |
"Email works" is the headline. Here's the machinery - and it's unglamorous. The wins come from restraint and relevance, not volume.
Forget the noise. Reconciled across the major benchmarks and adjusted for Apple's privacy inflation, the working open rate is one clean figure: about a third of emails get opened - 32%.
| Working open rate | 32% |
| Adjusted for Apple MPP | Yes |
| Basis | 1B+ tracked sends |
And email's case holds at the low end. 4.5 billion users. $36 back on every $1. A third of every send opened. Even the most conservative read still wins.
Email is older than most of the people who keep declaring it dead.
It is not loved. It is not new.
It just keeps paying.
Real benchmarks from the accounts we manage - from the share of revenue email & SMS drive, to campaign vs flow engagement. Filter by your category and see where you'd land against the median operator and the top quartile.
Methodology: Engagement and revenue-mix figures: aggregated, anonymized performance across the Klaviyo accounts we manage (May–June 2026). Revenue-share figures are normalized to a common attribution window so accounts compare like-for-like.
Open rates reflect post-MPP inflation - compare like-for-like.
YOCTO runs retention and lifecycle for fast-growing DTC brands. We'll run a free audit, hand you a written breakdown, and tell you honestly if we can help.