The economics on those deals look worse over time -- they're spending over $3 in guaranteed payments per $1 collected on those partner subscriptions, which meant partner subs went from being mildly profitable (gross) in 2020 to a $10mm cash sink in 2021. The good news is that overall the subsidized writers should be making enough for Substack to shut down the incentive payments (~$40mm in subscription revenue to writers vs $16mm in subsidies in 2021), so there's a good chance they can stop the bleeding. Still overvalued by at least 25x, though, and their OPEX is concerning; even if you ignore the $16mm in partner payments, they're still $6mm underwater on $10mm in revenue.