(Referring to "Videos and Premium Membership" posted by Jonathan) Those people who choose to use Apple Quicktime to view the videos should be aware of one thing. The viewing preference defaults to Flash Player, and you have to change the preference to Quicktime EACH TIME. At least that's my experience using Firefox on a Mac to visit Ballroomdancers.com. I'm one of the millions of people who have given up on Flash and its "upgrades" every two days to patch its many security holes. When I change (and save) my preference I can view the videos during that session. But if I close Firefox, the next time I come back to the site the preference is back to Flash.
This problem should go away when Ballroomdancers.com switches over to HTML5 video, but until then you may encounter the same situation I do.