
Substack's publication subscriber numbers have been growing rapidly, growing 3 to 5x per year. How much will that growth slow, if at all?
The last information Substack has released is that their platform first supported a million paid subscriptions as of November 2021.
I'll wait up to a year after the market closes on verified subscription numbers to resolve. If nothing has been released by then, I'll estimate to the best of my ability, based on confirmed or estimated information, like revenue, free subscriptions, pageviews, and the performance of individual substacks with public information.
Edit: I've extended the market to be open until right before I resolve, but to be clear 'by 2025' refers to the end of 2024.
Update 2025-11-01 (PST) (AI summary of creator comment): The market question asks about paid subscribers by 2025, which refers to by the end of 2024 (not end of 2025). The market close date is set to end of 2025 to allow 12 months after the measurement period to obtain accurate subscriber numbers before resolving.
resolves yes or no depending on how rules work
https://www.hollywoodreporter.com/business/business-news/substack-number-subscribers-video-trump-1236158048/
@strutheo confusing since the description says by end of 2024 but the date is end of 2025 ... so it might be no
@strutheo there is no ambiguity, please read the description. given the difficulty in getting accurate subscriber numbers, resolve (and market close) date is 12 months later. these are the relevant parts of the description 'I'll wait up to a year after the market closes on verified subscription numbers to resolve... Edit: I've extended the market to be open until right before I resolve, but to be clear 'by 2025' refers to the end of 2024.'
from https://sacra.com/research/convertkit-vs-beehiiv-vs-substack/

l’ve only spent too much time in the library and didn’t realize what the map of the territory looked like.
https://sacra.com/c/substack/ Has 2022 at roughly 2m. Via sacra.com : the competition

I speculate substack has gained enough popularity to overcome any disruptions from other startups now and is well known enough, that I speculate switching to DIY will become untenable if the churn rate is maintained even after switching over, in which case having links at substack for discovery by new users is the only way to sustain the growth for new subscribers to outpace or match the churn rate. I don’t know what the ceiling is for substack’s growth, but I suspect producing higher quality content will be in greater demand in the future than the present popularity of substack (its not near NYT level popularity) to nearly triple the 2002 level of subscribers in 3 years (150% growth year over year for the next two years from 2022 seems a tall order but feasible since they just did another fundraising round). This is pure speculation though without any domain knowledge.
They aren't really substack's subscribers though. Plus I think there are a lot more than 1mm paid subscribers right now. A lot more. Like approaching 5mm is my hunch. That isn't really that many when you consider it's just a total of all subscribers across all publications. Some subscribers pay for a dozen or more different pubs, which would presumably count as 12 subscribers, not 1. Each transaction is totally separate.

