A month ago, when Elon Musk’s Twitter first set out to revamp the Twitter Blue subscription, workers at the company identified a problem. Musk had promised that subscribers to the $8-a-month service would see half as many ads as free users. But that would cost the company about $6 in ad revenue per user per month, according to internal estimates. Factor in Apple’s App Store fees — something Musk would later go briefly to war with the company over — and the new Blue promised to lose the company money.

The launch of Blue was quickly derailed by abuse of the new verification system and mass impersonation of brands, just as employees had predicted, and Twitter went back to the drawing board. After a series of delays, on Monday the company relaunched Blue for a second time. Once again, it promised subscribers that benefits will include soon seeing 50 percent fewer ads than regular users.

It’s a bold move for a company that has already been forced to offer advertisers huge concessions to prevent them from fleeing. But behind the scenes, Twitter has been working on a plan that executives hope will make Blue profitable – forcing all Twitter users to opt in to personalized ads in order to keep using the app, Platformer has learned.