The Klaviyo lemon.
Some squeeze it with baby hands and get a couple sad drops.
Others wring it dry with a gorilla grip.
I got a reply from a reader last week.
"We don't send long emails because customers don't read them, I think."
It's a common belief.
I used to worry about attention spans too.
Then I looked at the data from our best-performing campaigns over the past 5 years.
10k emails.
With swiss-like precision, every single one of them was long-form (excluding sales announcements and closes, and product launches for obvious reasons).
Long-form emails work.
The person who deletes a long email without reading it was never going to buy anyway.
But the person who is considering buying from you is different.
They are an Investigator.
They joined the list because they are in the market for what you sell.
They are currently weighing you against a competitor or two.
They are looking for reasons to choose you.
They WANT to believe.
Short copy starves that decision-making process.
It gives them less information when they are desperate for more.
We've been working with Flatpack, a mattress company in New Zealand, for a year and a half now.
Their pitch is simple: "We are cheaper and just as good because we cut out the middleman."
The problem is that "cheaper and just as good" sounds like a scam in 2026.
Everyone claims it.
To make people believe it, we had to prove it.
We had to explain the "showroom tax". The salesmen's commissions. The "sounds good, doesn't work" features that have no benefit at all.
We had to adopt an "Us vs. Big Mattress" stance.
That takes length.
So we wrote long emails from Angus, the co-founder.
We let his personality shine through.
The result was 2-3x higher revenue per recipient compared to the average email.
Investigators read, and buy from, long-form emails.
If you want to get as much juice out of the Klaviyo list you currently have, I'd give them a try too.
-Matt
P.S. See examples in the video below