Freemium only works if free users become a growth engine and a clear slice of them hit a wall they'll pay to remove. Give away what's cheap to serve and gate what's tied to real value or scale (seats, usage, advanced features). If nobody's hitting a paywall naturally, you don't have freemium, you have a free product.
From theleanstartup.com by Eric Ries ~330 pages
The origin text for the modern MVP and validated-learning vocabulary every founder now uses. Read it for the mental model that a startup is a series of experiments, not a single bet.
From lennysnewsletter.com by Patrick Campbell (ProfitWell), via Lenny's Newsletter long-form guide
Patrick Campbell built ProfitWell on pricing data from thousands of companies, and this is the single best free deep-dive on SaaS pricing strategy. It's the canonical starting point for value metrics, segments, and packaging.
From lennysnewsletter.com by Lenny Rachitsky newsletter archive
Lenny's Newsletter is the most trusted operator-written resource on product, growth, and monetization, drawing on data from hundreds of companies. It's specific and tactical where most business-model writing is generic.