Snap Inc. has attracted more than 3 million users to its Snapchat+ subscription service, a $3.99-a-month offering that provided early access to features like its new artificial intelligence chatbot.

The growth has exceeded the company’s expectations and includes the addition of about a million paying users in the past 11 weeks, Snap said Wednesday at its annual partner summit, held in its hometown of Santa Monica, California. The service launched last year but got a boost in February when the company added exclusive access to a chatbot, called My AI, that’s powered by OpenAI’s GPT technology.