The newsletter start-up, which once drew an overture from Elon Musk, is betting on politics content and recruiting stars. But profits remain elusive. Substack Inc, Newsletters, News and News Media, United States Politics and Government, Social Media, Writing and Writers, Mergers, Acquisitions and Divestitures, Presidential Election of 2024, X (Formerly Twitter), Hasan, Mehdi (1979- ), Musk, Elon, Silver, Nate, Richardson, Heather Cox, Todd, Chuck (1972- ) The newsletter start-up, which once drew an overture from Elon Musk, is betting on politics content and recruiting stars. But profits remain elusive. NYT > Business