Facebook's Audience Network does NOT work for Video Retargeting OR Custom Audiences
I discovered this last week after a lot of back and forth with Facebook customer service. The video explains all of this, but I'll describe what happened here too.
I placed an ad on a video post which included showing the video on their Audience Network (Instagram and some other places). By default Facebook toggles on Audience Network and basically warns you against turning it off. For this particular ad they told me my video would be seen by 4% less people (remember that number 4%).
The beauty of advertising videos on Facebook is you can 1) target a particular audience and 2) retarget people that have watched a certain amount of that video: 10 seconds worth, 25% of it, and so on. Those are no longer "cold leads" for your business, because they NOW know something about you. And imagine if you advertised a lengthy 6 minute video, you'd sure want to target people that made it all the way through.
So after running the ad for a week or so, I had 8,179 people watch 10 seconds of it. I tried to create an Engagement Audience targeting people that watched 10 seconds. That should have been 8,179. Nope, every time I created the audience, it would show fewer than 1000 viewers.
This is why I contacted Facebook to say "hey, whats the deal, why is one number 8,179 and the other fewer than 1000". Well after a lot of back and forth, they finally revealed to me this...
8,169 people watched on the Audience Network
10 people watched on Facebook.
AND YOU CAN ONLY RETARGET TO THOSE WHO WATCHED ON FACEBOOK!!!
Mind blower. But it gets worse. The video was shown to 8,179 random people. These ads were intended to be for a particular audience from the start. I don't cold-advertise to any ol' Joe Shmoe, I had clear targeting goals from the start based on user interests, etc.
Here's an exact cut and paste from my exchange with customer service... "I was able to do some research for you and I was able to find some information. When creating a Custom Audience that is based on Engagement the Audience Network is not taken into consideration."
In other words, all money wasted.