Hyperlinks in video

I'm constantly amazed at how rarely the mother of invention on the web seems to be necessity. So often it seems to be more about "what if?" and "why not" and general envelope-pushing. Then begins the head-scratching (for mere mortals such as me, anyway) to come up with a way of making it really useful.

Anyway, being of little brain or imagination, I'm not sure yet what I'd do with the facility to attach notes and hyperlinks to people and things in videos, but I love the idea! This is what Asterpix (gettit?) does.

Here's an example: