I pulled segment data for one of our clients recently and the numbers stopped me cold.

Full list: 64,821 members. $1,633,373 in attributed email revenue.

Engaged 45 days: 33,592 members. $1,628,511 in attributed email revenue.

Half the list. $4,861 difference in revenue.

Take a second and actually sit with that.

Because if you're sending to your full list regularly, or even your engaged 90 or 180 day segments on a consistent basis, you are not generating meaningful incremental revenue from those extra subscribers.

You're paying a deliverability tax for reaching them if you’re sending to them often.

This is happening inside almost every Klaviyo account with over 15,000 subscribers. Most brands have no idea…

This is how to create a dead-simple segmentation strategy that scales…

Everyone in the email space talks about segmentation like complexity is a virtue. More segments, more rules, more behavioral splits, more conditions stacked on top of each other. The more intricate the setup the more advanced you must be.

That's mostly wrong.

Steve Jobs said it better than anyone ever has.

The brands running the healthiest email programs we manage aren't the ones with twenty segments and conditional logic for every possible subscriber behavior.

They're the ones who keep their core segments clean, protect them aggressively, and are ruthless about who gets included on any given send.

Simplicity isn't where you start. It's what you arrive at after you've seen enough over-engineered setups fall apart in practice.

Your engaged 30 to 45 day segment is your revenue segment. This is where the overwhelming majority of your attributed email revenue comes from and the data above proves it. Every promotional campaign, every launch, every time-sensitive offer goes here first.

Send here frequently. Protect it aggressively. And understand that every time you dilute a send by including less engaged subscribers around it, you are putting the results of this segment at risk.

Your engaged 60 to 90 day segment exists for one reason. To pull subscribers back into your engaged core. Not to generate campaign revenue. Send here occasionally, a few times a month at most, with content designed to earn an open or a click rather than push a sale.

Engaged 120 to 180 days gets a send once a month at most. Your full list gets used for Black Friday, a major product launch, or something genuinely significant. Nothing else.

The goal of every send outside your core is re-engagement. The moment you start treating outer tiers as a revenue source you start degrading the deliverability that makes your core segment work.

Here's where most segmentation advice stops short. Clean engaged segments aren't just about who you include. They're about who you explicitly exclude.

Three exclusions worth adding to every segment you send to:

Bounced 2x - Last 30 days: Subscribers who have bounced two or more times recently. Invalid addresses quietly dragging your sender score down with every campaign.

Exclusion segment: Email addresses that are likely not real people: emails with a plus sign in them, no-reply, support, amazon, tiktok, etc. These almost always indicate a spam trap, a test account, or a disposable address. Not real buyers.

Unengaged users: Subscribers who have received ten or more emails from you and have never clicked anything. They've seen enough to make a decision. The decision they've made is that they don't want to engage. Stop including them.

Now here's the part that changes how you think about this entirely.

You don't need separate complex segments for purchasers and non-purchasers.

You don't need to rebuild your segmentation strategy every time you want to tailor your messaging.

You just need two simple exclusions layered on top of your core engaged segments.

When you want to speak to non-purchasers, exclude anyone with at least one placed order.

When you want to speak to existing customers, exclude anyone with zero placed orders.

That's it. Same core engaged segments, you're just toggling one exclusion depending on who the message is for.

No extra segments, no additional complexity, no maintenance overhead.

The simplicity of your core segments stays completely intact.

A strict 45-day engagement window makes complete sense for a supplement brand where someone reorders every month.

It may make less sense for a furniture brand where the consideration cycle is 4-14 months.

Best practices are someone else's averages.

Your engagement windows should reflect how your specific customer actually behaves, not what a Klaviyo tutorial published three years ago suggests.

A brand selling consumables and a brand selling considered purchases need completely different segmentation logic and treating them the same is one of the most common and most costly mistakes we see.

Including new subscribers automatically in your engaged segments. This seems logical. They just signed up, they must be interested. The problem is if their email address has any kind of issue, it gets mailed regardless. New subscribers should earn their place in your engaged tiers through actual engagement, not just recency.

Using site activity as an engagement signal. On the surface, it makes sense as well. Someone visiting your site must be high-intent and ready to buy. But site activity and email engagement are completely different behavioral signals. Someone can browse your site every week and never open a single email. Including site visits as an engagement qualifier inflates your segment size and degrades the quality of the signal you're actually measuring. The result is a segment that looks healthy and performs worse than it should.

Everything above is a framework, not a formula.

The tier windows, the send frequencies, the exclusion thresholds, all of it needs to be calibrated to how your specific customer actually behaves.

A CPG brand and a furniture brand are playing completely different games and their segmentation should reflect that.

This is the part that's genuinely hard to do off a checklist. The logic is simple. The calibration is where most brands either get it wrong or default to whatever Klaviyo recommends and never revisit it.

If you want a segmentation strategy built around your actual customer data rather than industry averages, that's exactly what we do. We pull the numbers, look at how your list actually behaves, and build a segment structure that reflects reality rather than best practices written for someone else's brand.

Book a call and we'll show you exactly what your segments should look like.

— Anthony

P.S. The screenshot at the top of this newsletter is real data from a real account. 64,821 subscribers on the full list. 33,592 on the engaged 45-day segment. $4,861 difference in revenue. If your segmentation strategy doesn't reflect that reality yet, it's worth a conversation.