Tensions flare when it comes to principal media — the polarizing practice of reselling media inventory at an undisclosed margin. Critics claim conflicts of interest. Evangelists praise great rates. The reality? It’s a business necessity for advertisers and partners under budget and revenue pressure. When marketing, agency, and media executives apply transparency, principal media can be a winning strategy for all involved. This report helps media and other marketing executives understand how to apply disclosures to principal media programs.