"Let’s say, you have the minimum amount of break-points: desktop, tablet and small screen. A sales team has a template with Slot A (the primary slot) that accommodates a Leaderboard for the desktop. But then that changes to a MMU for tablet. And changes again to a thin banner for small screen. A sales person has to understand they’re selling ONE slot for this. And an advertiser has to understand they’re paying for ONE slot for this. However, they’re supplying three times the amount of creative. And this is just a very simple use case."