To estimate this growth, we anchor to the growth rate from two known data points from the US, and apply adjustments based on global growth, and to account for the slowdown.

Those two US data points are:

• Number of Plus subscribers in the US in March 2024 (3.9 million)[1]
• Number of Plus subscribers in the US in July 2023 (2 million)[1].

This growth rate is steep, so we model with a constant monthly growth rate over these 8 months.

For the first adjustment -US-to-global growth adjustment of 1.2- we estimate that global growth is 20% faster than US growth, as ChatGPT grew in the US first and globally later.

For the second adjustment -Slowdown adjustment of 0.5- we estimate that overall growth has slowed by 50%:

• the first five months from the release in February 2023 until July 2023 saw an increase of 2m users, whereas the following 8 months until March 2024 only saw an additional 1.9m.
• chat.openai.com has reported a net decrease in page visits in May 2024. In subscriptions track page visits, growth may even be negative.
• There is reason to believe that growth remains significant; since April, GPT-4o's release prompted the largest spike since launch in ChatGPT Plus mobile revenue[3]