well - i can only speak for myself - but I don't have the luxury of a large workout space and second televisions and dvd players, and I had to scrimp and scrape for my laptop for school purposes. Doing a lot of workouts (online or even with dvd) means being creative and limiting my range of motion. When i first got the balletbody downloads, I didn't have a burner or a place to do it either, but I knew eventually I would, and did the ones that I could.
If my burner was working I wouldn't hesitate one minute to help anyone who needed help burning things either.
But I can really understand why some people choose to do online downloads as
A: this is the nature of information right now. Instant and Streaming (see - Netflix, and other mediums like that)
B: it is less expensive. instead of having to rent out a workout space, and get music rights (because most people don't like the generic stuff anymore), having to get camera crews, and all of that other stuff. with a podclass format you get Them + Camera
C: It's a little more "informal" depending on the person.
D: you get more stuff.
I know there are people who just don't like dvds, and prefer the gym, and those who like dvds instead of the gym and now it's going to be some prefer the streaming than dvds or a combination of all three