Prune your list and stop trusting open rate

I grew my newsletter, Anywhere Income, to 12,000 subscribers, roughly 60% through paid ads and 40% organically, mostly from Twitter. Getting there taught me more about the cost of a bad subscriber than the value of a good one. This guide is the process and the thinking I’d follow, in plain terms, with the parts that are general industry fact separated from my own experience.

Why pruning matters

A subscriber who never opens or clicks still costs you in three ways:

1. Money. Most platforms bill by subscriber or contact count. beehiiv, Kit, MailerLite and AWeber all quote prices for a given list size on their pricing pages (see the pricing tracker). MailerLite, for instance, bills on active subscribers and excludes unsubscribed and bounced ones, but inactive people who are still subscribed count.
2. Deliverability. Mailbox providers watch how recipients react to your mail. A large block of people who ignore it, or worse mark it as spam, is a bad signal. Google’s published sender guidelines tell bulk senders to keep spam complaint rates low (it names 0.10% as a target and 0.30% as a level to stay below), and to authenticate mail and offer easy unsubscribe. See Google’s sender guidelines.
3. Decision quality. If a third of your list is dead weight, every average you look at is diluted. You’ll change the wrong things.

Cheap acquisition makes this worse. Refind cost me about $1.50 per engaged subscriber, and it only charges for subscribers who open within their first seven days. That sounds like a guarantee of quality, and it’s a fair model, but an open in week one doesn’t mean someone is still reading in month three. You still have to prune those subscribers regularly, or they quietly build up into the non-reading block that hurts deliverability. That’s not a reason never to use ad networks. It’s a reason to prune on a schedule and to judge a source by what its subscribers do after the first week, not by cost per subscriber.

Why open rate misleads

Open rate is measured by a tiny invisible image in the email loading. When it loads, the open is recorded. Apple’s Mail Privacy Protection, introduced in 2021, can load that image automatically on the recipient’s behalf, whether or not the person reads the email. The result is that opens from Apple Mail users who’ve enabled the feature can be recorded without any human attention.

What that means in practice:

• Open rates are inflated by an amount that depends on how many of your subscribers use Apple Mail with the feature on, so it differs from list to list and over time.
• Open rate comparisons between lists or periods are unreliable, because the mix of mail apps changes.
• “Subscribers who opened in the last 60 days” is a weak definition of active, because a person who has never read your email can still count as an opener.
• Other opens are also unreliable. Image blocking can hide real opens, and some security scanners load images too.

Open rate isn’t useless. A sharp drop in a single send, compared with your own recent sends, can still tell you something (a subject line, or a deliverability problem). But as a measure of whether a person is engaged, it’s no longer sound, and a recorded open on its own is a poor reason to keep someone.

There’s one place where opens still help: the absence of them. Apple’s prefetching adds opens that never happened; it doesn’t remove real ones. So a subscriber with no recorded opens at all over three months is very unlikely to be reading, which is why my pruning rule above uses it as the trigger for re-engagement emails. Lots of recorded opens, on the other hand, proves very little.

What to measure instead

Define your own “active subscriber” and don’t change the definition. For removal I use the simple floor above (no opens in about three months, then re-engagement emails). For judging whether a list or a source is worth anything, I look at replies and the actions people take after clicking.

How to prune: a step-by-step process

1. Back up first. Export your full list with signup dates, sources and engagement fields. Keep it somewhere safe.
2. Segment by source and age. Compare how subscribers from different sources behave. A segment from a cheap ad network that never clicks tells you something about the source.
3. Define inactive. My trigger is no opens at all in about three months; you can tighten it with clicks and replies if your platform reports them well. Exclude brand-new subscribers (for example those who joined in the last 30 days) so they get a fair chance to see your welcome sequence.
4. Send a re-engagement sequence to the inactive segment: a few “are you still interested?” emails, with a clear way to stay (“Do you still want this? Click here to stay”). Make it easy.
5. Remove or suppress the rest. Those who didn’t click or reply can be removed. If your platform allows suppressing, you keep the record and stop sending.
6. Watch the next few sends. Your list is smaller; check clicks per send, unsubscribes and spam complaints. They should look steadier, not worse.
7. Make it routine. With a three-month window, a quarterly prune fits naturally, and it matters most for a list that’s growing through paid acquisition.

Common mistakes

• Treating opens as proof of reading. No opens for three months is a useful trigger; lots of opens isn’t proof of anything (Apple prefetch). And image blocking can hide a real reader, which is why the re-engagement emails come before removal.
• Pruning new subscribers. They haven’t had time to engage.
• Deleting without a backup.
• Pruning once and forgetting. The problem comes back with every cheap source.
• Pruning to flatter the numbers. The aim is a healthier list, not a prettier dashboard.

Sequences and segments: the other half of list quality

Pruning removes people who aren’t engaging. Sequences and segments help the right people engage in the first place.

• A welcome sequence is the first few emails a new subscriber gets automatically. It sets expectations, delivers what you promised at signup, and asks for a first action (a click, a reply). It’s the cheapest way to improve early engagement, and it gives you the data you need to decide who’s active.
• Segments are groups of subscribers based on something you know: where they signed up, what they clicked, what they bought. Even two or three simple segments (new, engaged, inactive) let you send differently to each.

Which platform lets you do this on which plan matters. Kit lists sequences and visual automations from its Creator plan; MailerLite lists automations on its free plan; AWeber’s Lite plan lists three automations and one custom segment. Our reviews of Kit, MailerLite and AWeber show what’s included, and beehiiv lists automations from Lite.

Paid growth without wrecking your list

Roughly 60% of my subscribers came from paid ads and 40% organically, mostly from Twitter. They behave differently, so treat them as separate segments from day one.

• Tag every subscriber with a source. If your signup forms or platform allow it, record which ad, network or social channel brought them.
• Judge a source after 30 to 90 days, by replies and actions after the click, not by the cost of the signup. A Refind subscriber who opened in week one and nothing since is still a non-reader.
• Cap spend on sources that fail the test. A cheap subscriber who never clicks is more expensive than it looks, because you pay to store and email them.
• Be careful with incentives. Offers that attract people who only want the freebie tend to bring people who leave.

A pruning checklist you can copy

• Export and back up the full list.
• Add or confirm a source field on every subscriber.
• Define “inactive” (mine: no opens in about three months) and write the definition down.
• Exclude subscribers under 30 days old.
• Send a few “are you still interested?” re-engagement emails.
• Remove or suppress non-responders.
• Check the next three sends for clicks, unsubscribes and complaints.
• Review your acquisition sources against the results.
• Calendar the next prune.

Where this fits

This guide pairs with how to start a newsletter, which covers setting up for quality from day one, and how to switch platforms, which is a good moment to prune because you shouldn’t pay to migrate dead subscribers. If you’re comparing tools, our best newsletter platforms page and Mailchimp alternatives show how each prices a list. For who wrote this and what they have and haven’t tested, see about Lewis and how we review.