Podcasting is very hard work.
Videocasting would be insanely hard work.
This is because there are two very difficult parts to any successful effort in either- preproduction and post-production. Most people only see the effort as being the bit in the middle, which is what you say sitting in front of the mic or lens.
However, if you’ve done your pre-production work, that’s just an assembly job. Research on what you’re going to say, gathering suitable atmospherics and so on has to be prepared before you can press the record button. Then you have to do as many takes as you need to get a clean version. Then you have to do the hard part of editing these together in post production.
If your programme is to be, say 15 minutes (and sadly few enough podcasts are even that short) you need to budget about an hour and an half of solid work in post production and a level of pre production suitable for your topic, but at the very least a futher hour. As Damien points out, a lot of people realise that they can’t give that amount of time over to a bit of fun.
I rolled my way through the first three of my podcasts on artwork in the national gallery in a matter of a few months. Each one was only 3-4 minutes long. But they all took at least 2 weeks to research (tucked between the time spent doing all the other things in life).
And that was with a clear idea of what I wanted to say. When I ran out of preprepared pictures and had to stop and start examining works from scratch, I found it took forever.
I’ve prepared a further piece, but have yet to record it. And even when I do get around to sending episode four into the world, I certainly don’t expect to be hitting episode 5 any time before Christmas.
Podcasting is probably the only medium that allows for such time to be taken to get things right. So I’m in favour of it. But, that said, if I reach my target number of episodes, I’ll be re running them all. Weekly broadcast is only possible in a working life, I think, when you already have them in the can.
An honourable exception is An Timeall.