Home » YouTube Channel Growth » Which type of ad inventory is bought and sold based on a set, negotiated CPM. Which type of ad inventory is bought and sold based on a set, negotiated CPM. by Editorial Staff Advertisement 5shares Facebook LinkedIn Pinterest Twitter Email Enabled Reserve Auction Overage Join our listSubscribe to our mailing list and get interesting stuff and updates to your email inbox. Thank you for subscribing.Something went wrong.We respect your privacy and take protecting it seriously