Latest / The Newsletter Podcast with Fexingo: Substack, Beehiiv, and Email Newsletter Business / How Newsletters Use Cross-Promotion Swaps to Grow Subscribers
Transcript
- Lucas: So I was digging into Substack's network effects recently — how newsletters recommend each other — and I stumbled onto a really specific tactic that's been quietly driving a lot of growth for mid-sized writers. It's called the cross-promotion swap. Luna: I've seen that term pop up in a few creator communities. Is that basically when two newsletter writers trade a mention in each other's editions? Lucas: Exactly. But there's more to it than just trading a line. The most effective swaps are structured like a mini sponsorship. One newsletter runs a dedicated paragraph or a full section promoting the other, and then they swap. It's barter — no money changes hands. And the key is finding a partner whose audience overlaps with yours but isn't identical. Luna: Right, because if the overlap is too high, you're just talking to the same people. You don't actually expand your reach. Lucas: That's the trap a lot of people fall into. I talked to a Substack writer named Jenna who runs a newsletter called "Solopreneur Diaries" — about eight thousand subscribers. She wanted to grow, so she approached three other newsletters in adjacent spaces: one on remote work, one on productivity tools, and one on side hustles. Each had between five and twelve thousand subscribers. Luna: So she went for complementary niches. Smart. Did she just send them a cold email? Lucas: Pretty much. She wrote a short pitch explaining why their audiences would benefit from her content and offered to run a swap. Two of them said yes immediately. The third took a bit of convincing — they wanted to see her engagement metrics first. So she shared her open rates and click-through rates, which were solid — around 45% open rate and 8% click rate. Luna: That's above average for Substack, I think. So once they agreed, how did they structure the actual swap? Lucas: They agreed on a specific edition. Jenna would write a 150-word recommendation for the remote work newsletter in her next issue, and that writer would do the same for Jenna in their next issue. They used unique referral links — UTM parameters and Substack's built-in referral tracking — so each could see exactly how many new subscribers came from the swap. Luna: I love that they tracked it. Otherwise you're flying blind. What were the results? Lucas: Over six weeks, Jenna gained about 1,700 new subscribers from the three swaps combined. That's a 21% increase. Not huge in absolute terms, but for a newsletter at that scale, it's significant. And the cost was just the time to write those recommendations. No ad spend. Luna: Twenty-one percent is impressive. But I imagine not all swaps work that well. What are the common mistakes? Lucas: The biggest one is poor audience alignment. I had my own experience a couple years ago. I ran a swap with a finance newsletter — I thought, close enough, right? But their readers were mostly institutional investors, and my newsletter is about marketing for creators. The swap brought in maybe forty subscribers, and half of them unsubscribed within a week. Luna: Ouch. So the overlap was there on paper but not in practice. What's the minimum overlap you'd want? Lucas: Jenna told me she looks for at least 30% audience overlap based on topic interest. She checks by looking at the other newsletter's content — are they writing about things that would logically interest her readers? If it's too niche, the conversion drops. Another mistake is running the swap too often. If you do a swap every issue, your readers get annoyed. Luna: Yeah, you don't want to feel like your inbox is just a billboard. I've seen some newsletters that do a swap maybe once a month, and it feels like a curated recommendation rather than an ad. Lucas: Exactly. Frequency matters. I also think the call to action is critical. In Jenna's case, she didn't just say 'check out this newsletter.' She gave a specific reason: 'If you're trying to build a remote team, this newsletter has a great framework for onboarding.' That specificity drives clicks. Luna: So it's almost like writing a mini review. Speaking of which, there's a Beehiiv newsletter I follow called "The Auto Commute" — it's about electric vehicles and autonomous driving. They did a series of swaps with five different newsletters in the sustainability and tech space. Lucas: Oh, I've heard of that one. They grew really fast. What was their approach? Luna: They ran one swap per week for five weeks, each time with a different partner. They offered a free resource — like a PDF guide to EV tax credits — as a lead magnet within the swap. That increased conversions. By the end, they'd added over fifteen thousand subscribers. Lucas: That's a great twist. The lead magnet gives the swap more value. So it's not just a recommendation, it's a tangible offer. That likely boosted click-through rates significantly. Luna: Right. And they tracked everything with unique links. They found that the best-performing swap came from a newsletter about sustainable investing — that audience was highly motivated and had money to spend. The worst was from a general tech news roundup that had low engagement. Lucas: It reinforces the point that quality of audience matters more than size. A swap with a smaller but highly engaged list can outperform a larger but passive one. So for anyone listening who wants to try this, what's the first step? Luna: I'd say start by identifying three to five newsletters in adjacent niches. Check their content for a month to gauge quality and engagement. Then reach out with a personalized pitch that shows you've actually read their work. Lucas: And be ready to share your own metrics. Transparency builds trust. Also, decide on a tracking method early. Substack has its own referral dashboard, but you can also use a tool like Bitly or UTM links. Without tracking, you won't know what's working. Luna: It's also worth mentioning that the best swaps often lead to ongoing relationships. Some of the partners Jenna swapped with later collaborated on a joint webinar. So it's not just a one-time subscriber bump — it can open doors. Lucas: That's a good point. And if these kinds of marketing conversations have sparked something you've actually used in your own newsletter, we'd love to hear about it. Listener support is what keeps this show ad-free and independent. If you find value in what we do, you can buy me a coffee dot com slash fexingo — that's buy me a coffee dot com slash fexingo. Luna: Yeah, it really helps. And we're glad to keep these episodes focused on actionable strategies rather than ads. Alright, back to swaps — one thing I want to add: timing matters. Swaps tend to perform better when you time them around a big launch or a seasonal event. Lucas: Great point. Jenna scheduled her swaps just before she launched a paid tier, so the new subscribers arrived right when she had something to sell them. That's a smart way to maximize the ROI of a swap. So the takeaway: cross-promotion swaps are a low-cost, high-trust growth tactic — but only if you pick the right partner, track the results, and give your audience a specific reason to click. Luna: And don't overdo it. One swap per month feels like a recommendation. Every week feels like spam. It's a balance. Lucas: Exactly. Thanks for listening, and we'll be back with more newsletter strategies soon.