We have been doing a lot of work with videos for marketing purposes, which is a new area for me. Couple of things I have learned:
1) Short is better.
2) Video engagement metrics are evolving but in general web site visitors really like video content.
3) Generalize as much as possible because changing existing video is as expensive as creating new video.
4) Video done badly amplifies the negative much more profoundly than when video done well amplifies the positive.