Not to be self-promotional but the company I work at is tackling the problem in a way that at least helps 2 of those parties if not all 3 (unified.com). Albeit my commentary below is my own personal take.
Providing transparency to the marketers enables them to provide better targeting, more efficient spend, and in turn provide a better experience for their customers.
One other note pertaining to agencies. They'll continue to exist but the world where they can just blindly spend money is coming to an end. Previously they'd have a random ad buyer in the agency just go and spend the money. Those days are coming to an end and the free margin is going to instead go to reward those agencies that more effectively manage spend.
More transparency --> More insights --> More efficient spend --> Better overall experience.
Providing transparency to the marketers enables them to provide better targeting, more efficient spend, and in turn provide a better experience for their customers.
One other note pertaining to agencies. They'll continue to exist but the world where they can just blindly spend money is coming to an end. Previously they'd have a random ad buyer in the agency just go and spend the money. Those days are coming to an end and the free margin is going to instead go to reward those agencies that more effectively manage spend.
More transparency --> More insights --> More efficient spend --> Better overall experience.