This time, from Facebook. On their blog, Daniel Baulig writes
From development velocity to accessibility features, HTML5 offers a lot of benefits. Moving to HTML5 best enables us to continue to innovate quickly and at scale, given Facebook’s large size and complex needs.
One thing to note here is that HTML5 media works for facebook, despite their complex and scale needs. It works even better for simpler use-cases.
Not only did launching the HTML5 video player make development easier, but it also improved the video experience for people on Facebook. Videos now start playing faster. People like, comment, and share more on videos after the switch, and users have been reporting fewer bugs. People appear to be spending more time with video because of it. Videos are an enriching way to connect with the world around you, and we're happy we could make the Facebook video experience better.
This goes to show that the folks who've moved are very happy. That list is now large and encompasses more than 90% of all streaming on the Internet - YouTube, Netflix, Amazon, BBC, facebook and many more. If you're still using Flash to serve video, you really should reconsider.