If your campaign is clear without a case study video, please, for the love of all that is good, do not make a case study video. If you absolutely, positively, without a doubt cannot sum up your campaign in a short paragraph or a few bullet points, then and only then should you make me/us sit through a 2-minute case study video.
P.S. It goes without saying that you will spread your campaign message through twitter and allow people to share it via social media channels. That is not a concept in itself and does not warrant a case study video.
P.P.S. We have made this post into a handy jpg. Please feel free to blow it up, print it out and post it at your school/agency/barn. Godspeed.