It increases the brand awareness.
We could show your ads to people who had shown interest in your facebook page videos [We have found this strategy very powerful & the least expensive]
Make sure you write the tags for your videos. This will help facebook to ensure that these videos are shown to your right audience.
Facebook can help us to retarget people who watched a certain percentage of your videos. We are getting great results by retargeting video views on Ads. See the image below
We could create a lookalike audience of people who watched your videos & show your future ads to only those people.
You will see a increase in the quality of leads if you target people who watch 75% of the videos.
It takes a little time of yours to create the videos. However it will be absolutely worth it.