See your point Clare, but isn't this new set of hers targeted towards a much broader audience? Infomercials really do play to everyone, not just the fitness sector. While some may see that as unfair, I think those one on one things Tony Horton has done (is doing?) is setting up the groundwork for his new series.
Same or not, it's probably a gauge of future sales. I myself got the benefit of Cathe's BB series Timesaver before getting the others (it's a great stand alone too). Then too I did a lot of hers from TV, although I have to say they were more or less bought & paid for with my Direct TV subscription.
Not sure though why the lack of clips in the beginning? I saw the Peak infomercial, couldn't really get a lot from that about overall music, etc. the individual moves part though was really good. Rushfit has the preview of each disc, short but pretty good. Youtube is good for those montage type clips that give an idea of what it's like the whole way through.
One other thing about the systems (or individual DVDs), is people who have already completed it. Before video clips I would read many reviews from many sources to see if something would fit my needs, the Collage site, VF reviews, blogs, testimonials. Often the information in these & a good description to begin with is what, like word of mouth, will sell it to me.