Early AI training involved simple preference tasks. Now, training frontier models requires PhDs and top professionals to perform complex, hours-long tasks like building entire websites or explaining nuanced cancer topics. The demand is for deep, specialized expertise, not just generalist labor.

LLMs have hit a wall by scraping nearly all available public data. The next phase of AI development and competitive differentiation will come from training models on high-quality, proprietary data generated by human experts. This creates a booming "data as a service" industry for companies like Micro One that recruit and manage these experts.

The frontier of AI training is moving beyond humans ranking model outputs (RLHF). Now, high-skilled experts create detailed success criteria (like rubrics or unit tests), which an AI then uses to provide feedback to the main model at scale, a process called RLAIF.

For years, access to compute was the primary bottleneck in AI development. Now, as public web data is largely exhausted, the limiting factor is access to high-quality, proprietary data from enterprises and human experts. This shifts the focus from building massive infrastructure to forming data partnerships and expertise.

In a group of 100 experts training an AI, the top 10% will often drive the majority of the model's improvement. This creates a power law dynamic where the ability to source and identify this elite talent becomes a key competitive moat for AI labs and data providers.

Companies like OpenAI and Anthropic are spending billions creating simulated enterprise apps (RL gyms) where human experts train AI models on complex tasks. This has created a new, rapidly growing "AI trainer" job category, but its ultimate purpose is to automate those same expert roles.

A niche, services-heavy market has emerged where startups build bespoke, high-fidelity simulation environments for large AI labs. These deals command at least seven-figure price tags and are critical for training next-generation agentic models, despite the customer base being only a few major labs.

Merco's explosive growth and $10B valuation are less about its standalone business and more a direct proxy for the AI CapEx boom. With massive customer concentration among foundation models, its success is a high-leverage bet that AI giants will continue their massive spending on training for the next 3-5 years.

The demand from AI labs for high-skilled professionals (engineers, lawyers, doctors) to create evals and training data created a historic business opportunity. Mercor capitalized on this by creating an expert labor marketplace, becoming the fastest-growing company in history.