Upload a video
This is really handy if you have already got a video that you would like to include in your ad. You can do this at publish or come back and edit to add it later.
To upload a video into your ad, click the "Add Photos/Video" button:
Alternatively, if you already have your video on YouTube you can insert the link directly to your ad. You will see this option on the page, just click "add your own YouTube Video: