
Why the heck are those 'Do your thing Substack' posts going viral? Why do so many Notes go unseen? I dug into the algorithm to find out.
I've been on Substack for years, but ignored it until only recently.
What brought me back was the Substack recommendation feed.
The promise: You could reach other people interested in your writing easier by posting Notes and grow your community.
The reality: It's complicated.
As I started exploring the feed, I saw some confusing things. People were posting these 'Do Your Thing Substack' notes and getting huge numbers. Hundreds of comments and thousands of likes out of nowhere. Huh?
Then there were the Substack growth hackers posting 'Subscribe for Subscribe' notes and also growing quickly.
Posts with witty writing, interesting observations and links to long-form content were getting much less engagement comparatively.
I wanted to learn why so I searched and found a post by Mike Cohen, who is the Head of AI at Substack. He's the person responsible for designing the Notes feed. His post revealed a lot about the engine, including how:
- The algorithm picks content to show to you: It tracks your every move on Substack and uses that data to recommend content
- What content is favored: Content interest signals like likes, clicks and restacks play a big role
My biggest learning: The algorithm, isn't really tuned for quality. Instead, its purpose is to recommend content that will convert a reader into a free/paid subscriber.
That's why the 'Do your thing' Substack posts do so well. Conversion from reader, to subscriber to paid user is Substack's primary goal with the feed.
After completing my technical deep dive into the algorithm, here's what I've concluded about what I'd like Substack to do better:
- Highlight people's writing in the feed, not just Notes. LinkedIn gets a lot of flack, but the one thing they do well is send me notifications when people I'm following publish posts. (There might be a setting for this I'm not aware of.) I'm not sure how many followers are reading people's long-form newsletter content, and I thought that was one of Substack's strengths.)
- Fiddle with the engine weights: Obvious algorithm hacks like 'Do your Thing Substack' or Subscribe for Subscribe annoy a lot of people. They're low-effort. Many on Substack spend hours thinking about and writing fantastic content. I'd like to see these efforts rewarded more in the feed.
- Break the rich getting richer flywheel: A known weakness of recommendation engines is that they tend to over-promote the high-signal popular content at the expense of the long-tail. I see that happening on Substack where Notes from people with larger audiences get a large boost (because more people tend to interact with this content). So it's harder for smaller accounts to gain attention and an audience.
I think the Substack Note algorithm is a positive step forward. It has enabled me (once I was able to get my feed to stop showing me the 'grow your Substack to 1,000 subscribers in 30 days' stuff), to find some fantastic voices. But there's still a lot of room for improvement.
I know people's milage may vary with the feed. What's your take on how Substack has been doing with the recommendation engine now that it's been out for a while?