How to Succeed in SSP Buyer Development Amidst Vast Agency Data

Are you wrestling with the challenge of building new relationships and revenue streams while working for a major SSP? The vast landscape of 100,000s of seat IDs from numerous agencies using multiple DSPs can make it seem like an insurmountable task. How do you even begin to approach so many buyers, especially within large holding companies where each account is handled by sizable teams? Is there something I'm misunderstanding about the PMP/deals marketplace tool? Is this tool leveraged to connect with buyers on a large scale, since it sells multiple domains across different audience packages? Any guidance or strategies on how to navigate this would be incredibly helpful.