Personal AI agents that book, buy, research, write, and operate other software on a person's behalf moved from demos to products in 2025 and 2026, faster than anyone settled how they make money. They also break the arithmetic of the previous internet: search and social media served each extra user at almost no cost, so advertising could pay for everything, while an agent that reads dozens of pages, calls tools, and checks its own work spends real compute on every task. Across ten modules and 40 sessions, this collection works through the economics from the ground up: the capital stack underneath, what serving an agent actually costs, the price of everyday tasks, and the candidate revenue streams of subscriptions, usage pricing, commerce, advertising, enterprise, and devices. It then compares agents with the ad-funded web, social networks, utilities, and professional services, and lays out competing scenarios for who captures the value. Prices change fast, so every figure is a dated estimate and the method matters more than the number. The aim is a reader who can estimate what an agent task costs, judge whether a pricing model holds up, and test any claim about who will win.