Elon Musk’s Twitter Faces Exodus of Advertisers and Executives

nytimes.com

advertisers — who provide about 90 percent of Twitter’s revenue — are increasingly grappling with Mr. Musk’s ownership of the platform

Advertisers are 90% of Twitters revenue. What's the other 10%? Selling data? Licensing in-house tech? Something else?

Exactly. IIRC "data licencing" is about $400M/year which would make it more than 10% but still a relatively small part.