VC here: why? the market is fucking G I N U N G O (potentially). Email is a ubiquitous technology. Any platform that could potentially lead the monetisation of it is worth serious consideration. Substack is probably the company with the best traction today. Given that, I think there will be a land grab now with lots of copycats charging the same or less - limited moat. Doesn't mean the company can't grow to be a monster - see Shopify.