Make what happen exactly? C-level execs do not run ad campaigns. At most they'll defer to the CMO, who then just tells you to talk to their agency.

There are private marketplaces and other deals you can work out with agencies but this is usually for inventory against existing campaign RFPs, and comes with all of the typical creative requirements. They're not going to run an entirely custom campaign under your own terms and restrictions, not at any sustainable scale.