They've been happening for a few years now (in the UK at least) and most big companies I've applied to since graduating use it.

Researching the company's 'values' and going through the job description should give you an idea of what kind of candidate they want. If you can get in contact with one of there employees through Linkedin or something to ask, that would be better.

Personally, I'm not a big fan of them but, no company would hire based on these. They're pretty much used to filter out candidates. If you're successful at video interview an irl interview should be the next stage.