According to this [1] data which uses actual subscriptions instead of households, it seems the number is around 8-10million LLM subscribers in USA. This was March so I expect the figures to be around 40% higher now.
Another proxy: OpenAI said [2] they have 50M subscribers and in another place they said 40% of mobile revenue comes from USA. That itself accounts for 10M paid subscribers within USA which is 5 times the estimation from this post using ChatGPT alone, that too from February.
2) WoW will never be billed via a corporate card.
Regarding LLM: I guess if you count in enterprise/company subscription, LLMs would win. Interesting would be how many really want them or just have to use them…