Which of the below statements is true for private auction deals?
- Private auction deals allow you to pay a varied CPM across multiple sites.
- Private auction deals give an exclusive group of advertisers priority to bid on the open inventory.
- Private auction deals work on a 1st price auction where the highest bidder wins the impression, and pays the highest bid.
- Private auction deals work on a 2nd price auction where the highest bidder wins the impression, but pays the 2nd highest bid.
