A corporate video is something that is used for communicating with internal and external stakeholders of a business. One way that corporate video can be distinguished from traditional video advertising is the target audience. The intention of corporate videos is usually to cater a specific audience instead of the general public. Communication, presenting analytics, sharing data or even explaining a product could be done through a corporate video.
I do not think this is how most people use YouTube. YouTube videos are more like blog posts, and fit more effectively into the niche of content marketing. Sure, people will comment—but they do so in a manner similar to how they comment on blog posts. They come to view and digest videos, not necessarily share their thoughts about the day. Because of this, you should approach YouTube as content marketing instead of social media marketing.