It is the highest priority line item in DFP. These line items are trafficked as CPM or CPC or CPD(cost per day). Publisher will use this Line item type to run the Roadblock campaigns. To know more about Roadblock campaigns click this link https://adopspedia.com/2024/04/22/what-is-roadblock/.
While trafficking these kinds of line items we have to indicate the share-of-voice.
What is share-of-voice?
Share of voice will tell the sponsorship line items to serve the ads to the given percentage of the available inventory.
For example if we give 50% as a share of voice for a line item. And we are having 2 Million available inventory means then this line item will definitely serve 1million impression.
To Learn More about the sponsorship line items click the below link by google