There has been an increased focus on this lately, but why? There are two main drivers. First, the proliferation of header bidding means that most impressions are available via multiple supply paths for each impression, whereas in the past most impressions were only available via one path. With a diversity of paths by which to buy each impression, buyers have the option to control which path they buy through.
The other change driving increased interest in SPO is the suite of new tools available that give more visibility into the ecosystem. First, ads.txt made clear which paths publishers authorized to sell their inventory. More recently, sellers.json makes it clear who is actually getting paid when you buy an impression on an exchange (though only the “first hop” - ie who the exchange pays directly). Finally, to get past that first-hop limitation, the new RTB supply chain object gives buyers visibility into the entire supply chain for an impression.
Taken together, header bidding, ads.txt, sellers.json, and supply chain object give buyers both the reason and the tools to implement SPO policies.
To learn about the best practices for getting started with SPO, read on to our next article.