I doesn't work on my MacBook Pro or Mac Pro because it's a proprietary Windows only WMV format which isn't very web friendly. I can't even play it after it downloads! It also doesn't play on my iPad or iPhone which is the largest growing population of web users (i.e., tablets and mobile devices). So unless your web site is targeting PC users only, I would highly recommend that you use more web friendly format like MPEG4 and not a proprietary Windows only format.
[John Rofrano]" I would highly recommend that you use more web friendly format like MPEG4 and not a proprietary Windows only format."
I would not call WMV proprietary. It is an open format. Apple could support it if they want. They just do not want to, probably because they do not control it or just historic bad blood. The net effect is the same.
Microsoft does make free WMV plug-ins for Quicktime.
For the web MP4 with AVC video is the best choice.
[Norman Black]"For the web MP4 with AVC video is the best choice."
That was my point. I don't consider QuickTime a good format either because even though you can install QuickTime on Windows, it doesn't work by default. So while Windows Media Video may not be proprietary, it doesn't work with Mac OS by default but even more importantly it doesn't work on 99% of tablets and mobile devices at all, and these devices are quickly becoming the predominant web client.