On principle, I never watch videos on a computer. Almost never. I listen to audio a lot, usually while doing something else. But you can't watch a video and multitask. Videos require concentration, they require your time, and they must therefore achieve a much higher quality to be worth the effort.
Recently I've been deciding what's the ideal audio player to buy next, and -- this is really amazing -- it's going to be a video player. Studies show that, although every company that makes players is pushing video, few people watch video on those tiny screens. I've got an excuse! There are many university websites with fascinating lectures you can download for free, MIT, Oxford, Harvard, Princeton, etc., and most of these lectures are in a video format, usually MP4. It's a bit of a nuiscance to convert MP4 files to audio only, and I've had the experience of listening to lectures where the speaker pops up a slide, the audience gasps, and there's no clear explanation. So I'm thinking I can MOSTLY isten to video lectures, taking quick peeks to see what the speakers look like, or to see a slide. But really, I can be an audio guy and have much more good stuff within reach, if I buy a video player.