This is an excellent article by Robert Reinhardt on the benefits of Flash Video.

You can see the evidence of Flash Video on just about every major video-enhanced web site. Here’s just a few that have made the headlines:

• YouTube.com: This popular UGC (User Generated Content) site delivers all user-uploaded content as Flash Video (FLV).
• Google.com: The video search component of Google.com uses Flash Video (Flash Player 6 compatible, Sorenson Spark) for search results.
• MTV.com Overdrive: As of the end of summer 2006, MTV.com’s popular Overdrive web destination has switched from Windows Media to Flash Video.
• ABC.com: The ABC broadcast network currently features video clips in the Flash Video format, and uses real-time Flash Video streaming for their Emmy-winning Full Episode Streaming site, featuring full-length TV episodes with limited commercial breaks.
• NBC/Universal sites: NBC and its sister channels (Bravo, USA, SciFi, Telemundo) now use Flash Video to stream video clips of teasers, deleted scenes, and promotions.

The other video players on the market, such as Microsoft Windows Media, Apple QuickTime, and RealNetworks Real Player, used to be the mainstay on nearly every video-enabled web site. Now, they’re left scratching their heads as to why Flash Video has taken over major segments of the industry in so little time - it’s nearly an “about face” from many video distributors in this year alone.

Ubiquity

Flash Video content can be viewed on any Flash Player distributed in the last four years. Starting with Flash Player 6, Adobe (then Macromedia) added the Sorenson Spark codec to the player plug-in. Flash Player 6 is installed on over 96% of Internet-connected computers in mature markets, such as the US, Canada, Japan, and Europe. Flash Player 7 and 8 have adoption rates higher than 90%. The Flash Player is also widely distributed across multiple computer systems, including Microsoft Windows, Apple Mac OS 9 and X, and Linux. No other video player can boast that fact - more on the “numbers” later in this article.

Quality

Flash Player 8’s addition of the On2 VP6 codec has been a major driving force in the quick update of Flash Video on the web. Many online distributors felt that the quality of the Sorenson Spark codec simply was not good enough to carry their brand image on the web - Sorenson Spark, while processor - and RAM-friendly on a wide range of computers, just didn’t have great quality over low bitrates compared to those offered by Windows Media, QuickTime, and Real Player. With the new VP6 codec, however, image quality and definition improved greatly, especially at lower bitrates.