If you are using the DFP ad server instead of hardcoding the In-Stream CPM ad unit directly to the web page it will NOT collapse when no ads are available. Therefore you will need to set up a passback system to increase your overall ad fill.
This diagram shows our passback strategy recommendations. It includes:
- Combo of premium and DR ads: Native Ads “triple threat” of In-Stream CPM < IAB CPM < In-Stream CPC or IAB CPC unit
- Premium ads only with IAB Display as the second passback
- Premium ads only with IAB Display as the only passback