How this term is used here In this channel's material, the middle period (AI cost squeeze) names the stretch of an AI product's life after the early idea-and-build phase, when a startup must survive sustained cost pressure and the industry's structural pressures before it reaches a defensible business. The Building AI Products and Startups chapter frames it as one of the recurring challenges the featured founders — behind products like Granola — all navigated in the same general period: find ideas worth building, build fast, find the sticky core interaction, and then survive the expensive middle period before distributing and growing.