After overseeing some of the world’s top creative shops for more than three decades, Martin Sorrell no longer seems to think they play a crucial role in advertising. The prospectus for his new venture, S4 Capital, went live Tuesday. And while the 191-page document includes quite a bit of information about S4’s primary property, MediaMonks,… https://www.adweek.com/agencies/martin-sorrells-new-business-plan-cut-creative-agencies-out-of-the-loop-altogether/