Google makes those videos for a long time now and usually they actually make it happen. I think just because you know some situations where it didn't work, it is not correct to assume that it is always a bad idea. Very likely we have a lot of high tech stuff today because of this kind of videos. It's just a way of presenting your idea in a quite understandable and exciting way. There are of course other things like Powerpoint slides, blog posts and so on, but in in the end what you do just depends on your budget and your available skillset.