I've been wondering this too. They said on a podcast that the average usage is around $6 a day in credits but I really question that. If that's the case though and they do have a lot of Pro and higher tier subscribers that might be making up the difference.
"Claude Code is also the most direct way to consume Sonnet for coding, rather than going through all the hidden prompting and optimization than the other products do. You will feel that right away, as the average spend per user is $6/day on Claude Code compared to $20/mo for Cursor, for example. Apparently, there are some engineers inside of Anthropic that have spent >$1,000 in one day!"
Huge margins on API lol, there's a reason the guys from deepseek told everyone that its bullshit that the big boys aren't making money, research is expensive but the inference isn't especially with the comments that even Sam Altman mentioned regarding pricing per response for the chat clients.