Nearly half of Anthropic's sales come from just two customers: Amazon and Google. That single data point, reported by Calcalist, is the clearest signal yet of how concentrated revenue remains at the top of the AI model market — and how much the sector's leading labs depend on their own investors and infrastructure partners to hit their numbers.

The relationship is structural, not incidental. Amazon and Google are not just buyers of Anthropic's Claude models. Both companies have made multibillion-dollar investments in the startup, and both supply the cloud infrastructure Anthropic needs to train and serve those models. The commercial relationship runs in both directions: capital and compute flow into Anthropic; license and usage revenue flows back out.

For revenue teams and sales leaders watching the AI market, the number frames a specific question about deal concentration. When two counterparties account for close to 50% of sales, the effective pipeline math changes. A single renegotiation, a shift in a partner's internal AI strategy, or a decision by Amazon or Google to prioritize their own in-house models could move Anthropic's top line by double-digit percentages in a single quarter. No comparable disclosure ties specific win rates or cycle times to these deals, so what remains measured here is the concentration itself — the strategic dependency is inference, not reported fact.

The concentration also cuts the other way. Anthropic's models give Amazon's AWS and Google's Cloud a competitive product to sell against Microsoft's deep alignment with OpenAI. The near-half figure suggests both cloud giants treat Anthropic's technology as material to their own enterprise AI revenue, not merely a portfolio bet. That dual role — customer, investor, supplier, and distribution channel at once — is now the dominant commercial pattern among frontier AI labs.

What the report does not specify is how the figure breaks down. The near-50% share could combine direct model licensing, cloud consumption commitments, or revenue-share arrangements on tokens served through AWS and Google Cloud. Each structure carries different margin profiles and different renewal risks, and the headline number alone cannot separate them.

Expect the concentration question to sharpen as Anthropic pursues additional funding and expands its enterprise business. Every dollar of direct enterprise sales the company books dilutes the Amazon-Google share — and investors reading the next reported figures will be watching whether that share falls because the denominator is growing, or because the partners themselves are buying less.