Publishers offering "Out Of Home" spots

You buy physical ad spots, such as billboards, transit ads, elevator and in-store screens, and posters.

How it's sold: You book directly with the operator or through an OOH network, by site and period.
How to choose: Bought by location, not audience. The question is who walks past, not who follows. Elevator and in-store screens dominate several Asian markets the open web never indexes.
Time to book: Weeks, for printing and installation