AI startups are reporting unusually fast revenue growth as companies race to adopt generative AI, automation and AI infrastructure. Several startups say they are not only growing quickly, but also reaching each new revenue milestone in less time than the last.
The numbers are not always directly comparable. Some companies use annual recurring revenue, while others report annualized run-rate revenue, committed ARR or gross annualized revenue before contractor payouts. Gusto, by contrast, reported trailing 12-month revenue.
Even with those differences, the pattern is clear. AI-native startups and older software companies adding AI features are telling investors that their growth curves are accelerating.
Mercor and Anthropic Show Extreme Revenue Velocity
Mercor has reportedly crossed $2 billion in gross annualized revenue as of June, about four months after reaching $1 billion. The company hires domain experts to train, evaluate and refine AI models, giving AI labs specialised human data for fields such as finance, law, medicine and science.
The Information reported that Mercor’s latest figure is gross revenue run rate, meaning it reflects customer spending before payouts to contractors. That makes the number different from net revenue retained by the company, but it still shows how quickly demand for expert AI training data has grown.
Anthropic has also reported rapid acceleration. The Claude maker said in May that its run-rate revenue had crossed $47 billion earlier that month, up from more than $30 billion in April and about $9 billion at the end of 2025.
That pace has made Anthropic one of the clearest examples of enterprise AI demand turning into large-scale revenue. The company raised $65 billion in Series H funding in May at a $965 billion post-money valuation.
Enterprise AI Tools Gain Commercial Traction
Sierra, which builds AI agents for customer service, said it reached $150 million in ARR at the start of its third year. Co-founder and chief executive Bret Taylor later said the company reached $200 million in ARR after taking seven quarters to reach its first $100 million, then only two more quarters to add the next $100 million.
Glean said in May that it crossed $300 million in ARR. The enterprise AI search and assistant company said it reached that level 15 months after crossing $100 million, with the jump from $200 million to $300 million taking six months.
Glean’s growth reflects rising demand for AI tools that connect to internal company data. The company has positioned itself around enterprise context, arguing that AI assistants become more valuable when they can securely understand a company’s documents, apps and workflows.
Older Software Companies Also Benefit
The revenue acceleration is not limited to AI-native startups. Gusto, the HR and payroll software company, said in May that it had surpassed $1 billion in revenue while serving more than 500,000 small businesses.
Gusto said it had delivered five consecutive quarters of ARR acceleration. Its growth suggests that established software companies can also benefit from AI when they use it to improve existing workflows and expand product offerings.
Legal technology company Clio reported a similar pattern. The company said in May that it had surpassed $500 million in annual recurring revenue, after embedding more AI into its legal practice management platform.
Clio had crossed $200 million in ARR in mid-2024 and doubled that figure by late 2025. Its growth shows how AI is reshaping vertical software markets where professionals rely on large volumes of documents, workflows and specialised knowledge.
Together, these companies show why investors remain focused on AI revenue quality, not just user growth. The strongest cases are coming from startups that can show accelerating milestones, paying enterprise customers and clear demand for AI tools that save time or improve specialised work.
Featured image credits: Magnific.com
For more stories like it, click the +Follow button at the top of this page to follow us.