This is AI Frontiers. Today, AI is aggregating the aggregators. The platforms that spent 15 years building power by controlling demand are now becoming someone else's supply base. That is the core argument here, and it follows directly from Ben Thompson's aggregation theory. The idea that whoever controls the point where users discover information controls the economics of everyone upstream. Social platforms won the last era of the internet by pulling fragmented attention into a single feed. They did not need to own the content, they only needed to own the moment of discovery. Once they had that, creators, publishers, and brands had no choice but to play by their rules. Distribution control, behavioral visibility, monetization control, all flowed from that one position. Now a higher order aggregator has entered. Generative AI systems sit above the platforms that once mediated everything below them. They ingest, rank, summarize, and represent content through a new interface. The user no longer needs to move across networks and search results. The AI does the aggregation on their behalf. The mechanism is the same as before. The winning layer is the one that owns user demand and makes suppliers interchangeable. What changes is who is being made interchangeable. This time, it is the social platforms themselves. The distinction the newsletter draws is worth holding on to. What moves to AI interfaces is intent-driven attention, answers, recommendations, decisions. That is also the most monetizable share of attention. The platforms risk keeping the time and losing the moments that matter most. There is a concentration risk that follows from this. A small group of firms already controls compute, capital, training data, and specialized talent. If those same firms become the default answer layer, they gain power at two levels at once. Social platforms mediated visibility. Meta aggregators mediate judgment. That is a more durable position because it sits one layer above the feed. The governance implication is direct. Regulating only the visible content platform misses the actor that increasingly determines what users see, which sources are weighted, and which claims appear settled. The control point has moved and policy has not caught up. That's AI Frontiers.