One of the questions that comes up more often than anything is 'why not use Flash' for video delivery?
Before answering the question it's worth understanding what Flash is. Essentially, it's a lightweight graphics orientated application that can be loaded into web browsers. It's best known for its seamless animated graphics and is extentively used for banner and other online ads. The format comes from the same stable as Macromedia Director and Shockwave, which have been extensively used for CD ROM authoring and animating. So, it's not surprising that last year video capability was added.
There are two codecs that can be used. Sorenson, which has been widely used for delivering Quick Time on the internet and has impressively small file sizes, albeit with somewhat dodgy quality.
The other is from On2, a company that I first came across five years ago when I was very impressed by the standard of their codec for the Real Player. They have now added an interactive layer to their codec (which, incidentally can be replicated on Windows Media).
There's a good analysis of the different codecs and formats at the Library of Congress site.
Whereas the Flash codecs stand up at low data rates, they're pretty poor at higher data rates, and Windows Media already supports HD, so there's little or not future proofing in a site developed in Flash.
Flash is used by web designers worldwide to provide an enganing interface and the real compeition to this comes from using a technology called Ajax, which allows interface elements to be dynamic in a browser without refreshing (eg dragging and dropping elements of the web page).
From a developer's standpoint, Flash is great for quick and dirty implementations, which is why it's so often used for microsites and marketing orientated sites.
Flash is also useful for cross platform development - you can be reasonable certain that it will work the same on most browsers and on most platforms. However, the figures I've seen that claim 90% of computers have Flash installed seems widely inflated.
A major downside of Flash is that it is only now being ported onto mobile devices and is not available for games consoles and set top boxes.
The new version of Windows, Vista, also comes with some amazing new capabilities, and, of course, will not support Flash.
There is a school of thought that Microsoft will seek to rival Flash with a product called Sparkle. The downside is that you need a PhD in applied computing to use it.
Another issue with Flash is scalability. Windows Media has a very robust architecture that scales well. You can easily serve hundreds of thousands of viewers if you have a network that's big enough. Although I haven't seen any studies comparing Flash serving technology with Windows 2003 Enterprise Edition's media serving capabilities, I wouldn't want to launch a major channel initiative on Flash just at the moment.
Other problems with Flash include the lack of support for live events, a poor database model and compatibility that hampers the development of sophisticated content management systems (it was interesting to note our rivals Brightcove's recent takeover of Metastories). They have a long way to go to develop a system as sophisticated as Narrowstep's telvOS.
So, if you're planning a marketing project with video, Flash may be the right tool to use, but for now, Windows Media is a far more robust and proven platform, even if it has its drawbacks.