While AI hype at the moment is concentrated on model and AI-native companies, AI use cases among non-AI-native companies within the “long tail” are growing more prominent and commonplace, ranging from customer service chatbots to augmented reality shopping experiences. Given the pace of AI innovation, we believe the easiest way to understand how companies in the long tail are using AI is by grouping their use cases into one of four layers that we outlined in this deep dive: custom models, closed-source models, open-source models, and third-party AI tools.