Advertisers are often buying a path, not a publisher. Direct SDK supply shortens that path: the impression comes from an app or site that integrated TapMind, not from an exchange that bought it from someone else.
Why the path matters
Fewer hops means a clearer view of where the ad ran and fewer places for the bid to be marked up before it reaches the publisher. It also means the supply rules — format, geo, app — can be applied at the source.
What it is not
It is not a promise that every impression is exclusive, and it is not a replacement for the measurement you already trust. It is a supply type you can target, cap and report on its own.