Substack Raises $100 Million, Betting on Subscriptions but Coming Around to Ads Substack, originally a newsletter service, says its app now has millions of users interacting with its creators.

App downloads for the Substack app on iOS have shot up from 7,752 global daily installs on October 31 to 17,382 as of November 3, according to data from Appfigures.

On Substack, for example, subscribers can see a list of publications they pay for, but not a full count. They also must click through individual invoices to see how much they are paying — a ...

Luckily there’s this thing called Substack.” McWhorter’s Substack became so popular that the book eventually sold to Portfolio, an imprint of Penguin, and is due out this fall.