My Growth Currency⚡ newsletter just added ~1000 subscribers in March. I went from 3k subscribers to 4k.

And nearly 100% of those subscribers were all thanks to one growth strategy: Recommendations.

Friends, I have not encountered a stronger growth strategy — free OR paid — than the latest Recommendations feature widget.

It’s a game-changer.

I’ve had dozens of newsletter strategy calls with newsletter publishers over the last 6 months. The #1 challenge they have in common?

“Growing my newsletter.”

Growing a newsletter is f*cking hard.

The best way used to be a valuable lead magnet. It can still be a great strategy. Newsletter swaps — aka “cross-promotions” — can also work. The demand for cross-promotions has spawned platforms like Lettergrowth, Collabmatch, and InboxReads, to name a few.

But the Recommendations strategy is leaving other strategies in its wake.

This article will cover:

  • What the newsletter Recommendations feature is
  • The best newsletter Recommendations tools
  • How to use it for your newsletter (how to get recommended)
  • Are Recommendations the right growth strategy for you?
  • Important considerations with this growth strategy

Let’s get into it and GROW your newsletter.

What are Newsletter Recommendations widgets?

A recommendations widget is a pop-up that appears when you subscribe to a newsletter, recommending a few other newsletter publications to subscribe to.

(SparkLoop’s Upscribe recommendation widget via

The subscriber can choose to sign-up for all the recommended newsletters, select only a few, or choose none.

These widgets aren’t new.

Major media publications have used them for a long time—commonly referred to in the industry as “co-registration” (aka. co-reg). Massive newsletters you know have used co-reg to acquire most of their subscribers. I’ve been told as much by paid growth experts.

Media companies with big budgets developed the tech for co-reg widgets. Until recently, no functional SaaS tools for the indie newsletter were available. So while this strategy isn’t new to email newsletters, it is new to the smaller indie newsletter publisher.

But now that they’ve arrived, their mere existence won’t guarantee growth. To be effective, these recommendation tools rely on 3 key factors:

  • reciprocity,
  • incentive, and
  • audience.


“Recommend mine, I’ll recommend yours.”

It’s like 5th grade when Jared gave you the Gushers from his lunch and you gave him your Dunkaroos.

Small-to-medium-sized newsletter operators without big (or any) budgets rely on the principle of reciprocity. Substack is relying on this principle. So is beehiiv. And it’s what ConvertKit is basing their upcoming Creaetor Network on (more on each shortly).

The “free” network effects of reciprocity have a snowball effect on growth, but the degree of that effect will vary.


Faster growth needs a steeper hill — financial incentive. Trading Dunkaroos for Gushers is great. But what if you could just give Jared $100 and raid his mom’s pantry? Jared’s happy, and so are you.

That’s what SparkLoop is doing with Upscribe, Partner Programs, and their Partner Network: subscriber acquisition. It’s what the big media players did with co-reg. And, it’s what some publishers are doing with Facebook ads, too.

(Admittedly, the pantry-raiding metaphor fails to capture the magnitude of potential here.)


A small audience won’t get it done. You need a substantial audience to see an impact on paid recommendation growth. Your Twitter pal Tina has 1,377 subscribers and can drive you a paid recommendation here and there. But Maria’s DTC newsletter has 137,700 subscribers and can blow your monthly budget spend in a long weekend (if you’re paying). Tina is nice but isn’t going to get you the growth you want and need, like Maria can.

The Best Newsletter Recommendation Tools

Some of the biggest ESPs are building Recommendation widgets to increase the value of their platform and build out valuable network effects.

Here are the major players — in chronological order of when each was launched:


Substack was the first established ESP to build out a Recommendations feature. They announced the launch in April of 2022.

Subscribing to a Substack newsletter with an activated Recommendations feature will display other Substack newsletters the publisher recommends you subscribe to.


A Substack publisher can choose a newsletter(s) to recommend. Recommending other newsletters helps them grow — but will it help you grow your Substack?

Probably. Why?

Because Substack is leveraging the principle of reciprocity. Just look how they’ve laid out the dashboard:

It displays any publications recommending yours — plus how many subscribers they’ve generated for you.

Important to note: you're only able to recommend other Substack newsletters.


beehiiv launched their built-in Recommendations feature in September 2022. It works much like Substack’s where a user is prompted to subscribe to other newsletters during the initial sign-up process.

Recommendations page from The Morning Huddle on beehiiv

You can access the feature with their free Launch plan.

Much like Substack, beehiiv is using Recommendations to increase the value of its platform—and the success of newsletters growing on its platform.


Unlike Substack & beehiiv, SparkLoop isn’t an ESP — instead, they’ve developed the first tool that allows most major ESPs to include a recommendations widget (or page) in the subscribe process.

The tool is called Upscribe, and it’s free to use.

And it’s perhaps the sexiest tool of the bunch. Launched in late 2022, Upscribe is changing the game for growth and monetization — yes, monetization too!


From a user experience, it works much like the other recommendation features discussed.

But since it’s not a tool within an ESP, Upscribe requires a little more effort to set it up. But it’s well worth it.

SparkLoop’s made the setup process simple with an easy-to-follow onboarding checklist walking users through the setup in “about 21 minutes”.

Onboarding checklist to get Upscribe set up

Monetization is possible thanks to SparkLoop’s Partner Program. A partner program allows a newsletter operator to pay for referred subscribers. The newsletter operator sets:

  • the price they’re willing to pay per approved subscriber (ranging from $2–$5 )
  • the maximum monthly budget a partner can earn by sending them referrals
  • the total monthly budget they’re willing to pay for approved referrals

Important to note: partner programs must meet certain requirements,including a minimum monthly budget spend of $2,000 (USD) per month.

Once a partner program is live, thousands of partners in SparkLoop’s Partner Network can share & promote the newsletter, making money doing so — most easily when they include it in Upscribe:

The backend look at the Upscribe editor in SparkLoop

Savvy newsletter operators are growing & monetizing:

  • they’re creating partner programs to pay for qualified referrals (paid growth)
  • they’re using Upscribe to earn referral revenue (paid promotion)

Done effectively, the earnings could negate the cost of their partner program’s referrals (ie. paying $2 per referral, earning $2 per referral).

There’s the opportunity to grow at no cost.


ConvertKit is building a Recommendations widget too.

They recently closed waitlist applications for their yet-to-be-launched Creator Network. The ConvertKit Creator Network will feature different ConvertKit newsletter publishers — much like the SparkLoop Partner Network — who can both recommend and be recommended by other ConvertKit newsletters.

The program is still in beta but a public launch is expected Summer 2023.

Should You Use Recommendations For Growth?

Everyone hates this answer, but it depends.

Maybe a better question is: what have you got to lose?

With growth comes sacrifice. Here are the most common things you might sacrifice with growth via Recommendations.


There’s been concern with the quality of subscribers recommendation tools deliver. After all, a new subscriber from a recommendation didn’t seek out your newsletter and sign up. Will they actually engage? Or will they lie dormant, never engage, and drive down your metrics?

Plus, most of these tools do not require double opt-in. They bypass it completely. So when a subscriber ticks the recommendation box and subscribes, they’re confirmed on your list.

So smart newsletter operators have protocols (sequences & automation) in place to ensure subscribers who don’t engage are quickly filtered and removed. But it doesn’t have to be complex.

→ It can be as simple as tagging a new recommended subscriber and putting them in a new welcome sequence.

» Managing subscribers referred via your Partner Program


More subscribers could result in lower engagement rates, like opens & clicks. This matters if you’re making money with ads & sponsorships. Engagement drives revenue and determines the success of your sponsor’s campaign.

So if you don’t have the right protocols in place to filter out the low-quality subscribers, your engagement metrics will suffer. As will your ad revenue.

» Partner Program subscriber quality guide


Cost is two-fold: acquiring subscribers (ie. with a SparkLoop partner program) costs money. If you can’t afford it — or can’t justify the spend — don’t do it. Also, more subscribers mean more money spent on your ESP subscription. Your operating costs could rise quickly (with some ESPs) as you gain subscribers.

What Else?

We’ve covered a lot here — but there’s still more to cover.

To avoid a 5k word article, I’m saving some important ‘recommendations’ topics for the next one.

I’m a big believer in this growth strategy. But there are some basic guardrails every newsletter experimenting with paid growth should consider.

So next article will diver deeper into what to do to ensure you don’t do what I made the mistake of doing…. 😬

Subscribe if you don’t want to miss it ;)