I think this move is significant for two reasons.

The first is that the Ankler was one of Substack’s largest publishers and early success stories. While its founding technically predates Substack — I’m pretty sure it started out on Mailchimp — it really came to prominence after Richard Rushfield migrated to the platform. That imprimatur gave Substack added legitimacy as a place where serious media entrepreneurs could launch their startups.

But what’s perhaps even more interesting about this move is what it says about Substack’s network effects. As I’ve documented in my newsletter over the past few years, Substack has built out a suite of tools that allow creators to tap into the platform’s growing ecosystem and grow their audiences. It started with its Recommendations feature and has since grown into a centralized social network.

The reason behind this strategy is that it helps Substack justify its 10% cut. Without these growth mechanisms in place, a creator would be financially incentivized to leave the platform after reaching a certain subscription threshold. You stay on Substack because it helps you grow your audience.

As one of the oldest and most prominent publications on Substack, the Ankler was probably one of the largest beneficiaries of these network effects, and yet it decided it was still worth it to leave.

Or at least mostly leave — Rushfield also announced he’s launching a free spinoff newsletter that will continue to publish through Substack.

In some ways, this represents an even greater threat to Substack’s bottom line. Think about it:

Let’s say you’re a publisher who starts seeing moderate success with paid subscriptions on Substack. Then you decide to migrate your Stripe account to Beehiiv and run your paid newsletter there. But you also continue sending a free version of the newsletter out via Substack.

This would allow you to continue drafting off Substack’s network effects without having to pay its 10% tax. Sure, you’d technically be operating two separate newsletters — which would add some extra friction — but that tradeoff might be worth it.

Right now, the Ankler is the only publisher I’ve come across that’s leveraging this strategy, but if it were to be adopted more widely, then that could become a huge problem for Substack, since its only way of generating revenue is through its 10% cut. This is precisely why Apple barred iOS apps from linking to (or even mentioning) alternate payment options.