There are issues that the publication author Kirsten Han misses about Substack. They only aren’t sufficient to outweigh the downsides.

She disliked how the platform portrayed itself as a haven for unbiased writers with fewer sources whereas providing six-figure advances to a number of distinguished white males. The hands-off content material moderation coverage, which allowed transphobic and anti-vaccine language, didn’t sit nicely together with her. She additionally didn’t like incomes $20,000 in subscription income, after which giving up $2,600 in charges to Substack and its cost processor.

So final yr, Ms. Han moved her publication, We, The Residents, to a competing service. She now pays $780 a yr to publish by means of Ghost, however stated she nonetheless made roughly the identical in subscriptions.

“It wasn’t too laborious,” she stated. “I checked out a couple of choices that individuals had been speaking about.”

Not way back, Substack haunted mainstream media executives, poaching their star writers, luring their readers and, they feared, threatening their viability. Flush with enterprise cash, the start-up was stated to be “the media future.”

However now, Substack finds itself not a wunderkind however an organization going through a bunch of challenges. Relying on whom you speak to, these challenges are both commonplace start-up rising pains or threats to the corporate’s future.

Tech giants, information retailers and different corporations have launched competing publication platforms previously yr. Customers who loaded up on newsletters in the course of the pandemic started to cut back. And lots of in style writers left, such because the affiliate English professor Grace Lavery and the local weather journalists Mary Annaïse Heglar and Amy Westervelt, usually complaining concerning the firm’s moderation coverage or the strain to always ship.

“Substack is at a pivot level the place it wants to consider what it’s going to be when it grows up,” stated Nikki Usher, an affiliate journalism professor on the College of Illinois Urbana-Champaign.

The excellent news for the corporate, 5 years outdated this summer season, is that it’s nonetheless rising. Paid subscriptions to its tons of of hundreds of newsletters exploded to a couple of million late final yr from 50,000 in mid-2019. (The corporate gained’t disclose the variety of free subscribers.) A hiring spree hopes to internet greater than a dozen engineers, product managers and different specialists. Executives hope to ultimately take the corporate — which has raised greater than $82 million and is alleged to be valued at $650 million — public.

However to keep up that development, Substack executives say, the corporate should provide greater than newsletters.

In an interview at Substack’s workplace in downtown San Francisco, its co-founders spoke in sweeping statements concerning the “grand Substack principle” and “grasp plan.” Chris Finest, the chief government, described a want to “shift how we expertise tradition on the web” and to convey “artwork into the world.”

“Substack in its fullest ambition is form of this alternate universe on the web” he stated.

In apply, meaning Substack might be not only a supply channel for written newsletters however extra of a multimedia group. Executives need customers to create “private media empires” utilizing textual content, video and audio, and talk with subscribers by means of expanded comments that would characteristic GIF photos and profiles for readers. This week, Substack will announce new instruments for writers to advocate different newsletters.

Jairaj Sethi, a co-founder and the chief expertise officer, described a imaginative and prescient of subscribers assembling round writers like followers at a live performance.

“For those who simply give them a spot to congregate and to work together with one another, there’s some fairly cool sorts of bonding,” he stated.

In March, Substack launched an app that consolidates subscriptions in a single place reasonably than dispersing them individually through e mail. This month, the corporate introduced a podcasting enlargement.

“Proper from the beginning, we’ve been intending for the corporate to do extra than simply present subscription publishing instruments,” Hamish McKenzie, a co-founder and the chief working officer, wrote concerning the app.

However as Substack evolves past newsletters, it dangers wanting like one other social community or information writer — which might make it much less interesting for writers.

Ben Thompson, whose tech-focused Stratechery publication impressed Substack, wrote final month that Substack has gone from being a “Faceless Writer” behind the scenes to making an attempt to place “the Substack model front-and-center,” increase its app as a vacation spot on the backs of writers.

“It is a method for Substack to draft off of their recognition to construct an alternate income mannequin that entails readers paying for Substack first, and publishers second, as a substitute of the opposite method round,” Mr. Thompson wrote.

Publishing on Substack is free, however writers who cost for subscriptions pay 10 p.c of their income to Substack and three p.c to its cost processor, Stripe. The corporate additionally provides hefty advances to a small group of writers, whose identities it refuses to expose.

Substack has one key distinction from most different media corporations: It refuses to chase promoting {dollars}. “Over my dead body,” Mr. McKenzie as soon as wrote. “The antithesis of what Substack needs to be,” Mr. Finest stated.

“If we, by means of greed or error, acquired into that recreation, we’d successfully be competing with the TikToks and the Twitters and the Facebooks of the world, which is simply not the competitors that we need to be in” Mr. Finest added.

Which means that Substack continues to depend on subscription income. Subscribers pay greater than $20 million a yr to learn Substack’s high 10 writers. Essentially the most profitable is the historical past professor Heather Cox Richardson, who has greater than 1,000,000 subscribers. Different notable writers embody the knighted novelist Salman Rushdie, the punk poet laureate Patti Smith and the Eisner-winning comedian e-book author James Tynion IV.

Emily Oster, an writer and economics professor at Brown College who has provided divisive recommendation on dealing with the pandemic with kids, joined Substack in 2020 after Mr. McKenzie recruited her. Her publication, ParentData, has greater than 100,000 subscribers, together with greater than 1,000 paying readers.

“Substack has turn into actually an even bigger a part of the media panorama than I had ever thought it might be,” she stated.

However Dr. Oster’s main sources of revenue stay her instructing and her books; a lot of her publication income goes towards modifying and help companies. Most customers have struggled to help themselves by writing completely on the platform and as a substitute use their earnings to complement different paychecks.

Elizabeth Spiers, a Democratic digital strategist and journalist, stated she gave up her Substack final yr as a result of she didn’t have sufficient time or paying readers to justify her lengthy weekly essays.

“Additionally, I began getting extra paid assignments elsewhere, and it didn’t make quite a lot of sense to maintain placing stuff on Substack,” she stated.

However Substack’s largest battle has been over content material moderation.

Mr. McKenzie, a former journalist, describes Substack as an antidote to the eye economic system, a “nicer place” the place writers are “rewarded for various issues, not throwing tomatoes at their opponents.”

Critics say the platform recruits (and subsequently endorses) tradition struggle provocateurs and is a hotbed for hate speech and misinformation. Final yr, many writers deserted Substack over its inaction on transphobic content material. This yr, The Heart for Countering Digital Hate stated anti-vaccine newsletters on Substack generate no less than $2.5 million in annual income. The expertise author Charlie Warzel, who left a job at The New York Occasions to write down a Substack publication, described the platform as a spot for “internecine web beefs.”

Substack has resisted strain to be extra selective about what it permits on its platform. Staff of Twitter who apprehensive that its content material moderation insurance policies can be relaxed by Elon Musk, the world’s richest man and the platform’s largest shareholder, had been informed to not bother applying for jobs at Substack.

“We don’t aspire to be the arbiter of claiming, ‘Eat your greens,’” Mr. Finest stated. “If we agree with or like every little thing on Substack, that may be falling in need of what a wholesome mental local weather seems like.”

Substack makes it straightforward for writers to interrupt away, and defectors have a fast-growing assortment of rivals ready to welcome them.

Previously yr, publication choices debuted from Twitter, LinkedIn, Fb, Axios, Forbes and a former Condé Nast editor. The Occasions made a number of newsletters out there solely to subscribers final yr. Mr. Warzel moved his Galaxy Mind from Substack to The Atlantic as a part of its newsletters push in November.

The media platform Ghost, billed as “the unbiased Substack various,” has a concierge service to assist Substack customers transition their work. Medium pared again its editorial publications to pursue a extra Substackian mannequin of “supporting unbiased voices.” Zestworld, a brand new subscription-based comics platform, has been referred to as “Substack with out the transphobia.”

Mr. Finest stated he welcomed the rivalry.

“The one factor worse than being copied will not be being copied,” he stated.