An advertiser who wants to target specific categories of video content on the Display Network should:
- add the keyword “video” to the campaign
- add a remarketing list to the campaign
- use AdWords for video
- create a Search Network with Display Select campaign
or
- target the Search Network
- use video ads
- add a call-to-action (CTA) overlay to the ads
- add the keyword “video” to the campaign
Explanation:
In AdWords, you can create compelling video campaigns with a range of video ad formats to engage customers in different ways on YouTube and across video partner sites. Available video ad formats include: TrueView in-stream ads, TrueView video discovery ads, and bumper ads. While video ad content must be hosted on YouTube, video ads can appear on YouTube and on video partner sites and apps across the Display Network, including on tablets and mobile devices (depending on your format and settings).
Source
You can create compelling video campaigns with a range of video ad formats to engage customers in different ways on YouTube and across video partner sites.
Read more here: https://support.google.com/adwords/answer/2375464