I downloaded one of their free flyers and found was a MP4 video.
I tried two things, I first uploaded the video into my YouTube account and linked to a email setup in Contact Contact it using your existing YouTube interface.
On my email, I first you have to click the arrow in the contained picture to start it, it did run.
However it didn't run continuously and when the video finished it stopped and waited to be clicked again to run again. There were other problems running and I messed around with it for a while but didn't get it resolved.
Ultimately, I feel that YouTube is setup for different usage and setting it up cleanly to continuously run a 10 second video is far messier than it needs to be.
Plus my screen showed all the You Tube signage all around the outside of the flyer picture. I think you need to automatically zoom in to the picture on invoking it and show the video only, I didn't see a YouTube controls way of automatically way of doing that as well, but it shows what I mean.
Second I then uploaded that same MP4 video a one page Wix website I setup, and I set it up so when I click the picture in constant contact it invoked the video contained in Wix. The video ran and I easily got it running continuously via Wix controls.
The only drawback I saw is that 1)One had to click the arrow on the Contact Contact picture (it didn't start automatically) to invoke the motion in the flyer and secondly the video took 5 or 6 seconds to start running after I clicked it. The time seemed excessive.