Time. We are a very small team. It will happen eventually, but at least now everyone has an option.

That's a perfectly fair argument. For those who want to embrace HTML5, which flash-based features in the main site weren't ready to be ported to HTML5 due to technical limitations? As one of the few sites even trying, your use case could drive HTML5 audio.

The main site actually used to be 100% Flash (Flex). We've ported nearly everything out now but there are some algorithms that are still in there for no other reason than never getting around to porting them, but the other thing we rely pretty heavily on Flash for is cross domain communication with 3rd party services, many of them don't support or know about CORS/jsonp but getting them to add a crossdomain.xml on their site was easy. We'll probably just disable support for those services for people who don't have Flash. We'll also probably prefer to use flash whenever it is available for playback, because so far for the most part HTML5 audio is still more flaky and gives us less control over buffering/playback than Flash does...but at least the basic aspects of the site that most people care about will be able to work seamlessly whether or not you have flash. Eventually. :)

+1! Thank you for the thought out response! Seriously - your company should share it more broadly. You have a rare perspective on HTML5's audio story. Most folks have only focused on video.

I'm curious where 3rd party services come in in slightly more detail - I'd always assumed what I saw on grooveshark was a 100% client-server app. I'm assuming they're something like pulling from an album art service or a similarly ornamental interface that wasn't even worth carrying over to the mobile experience.

What's "flaky" mean? Do you mean that using it sometimes resulted in failure to deliver audio to a user with a compatible user-agent? If so, that sucks. Which browsers, any ideas what's wrong with it? If not - could you clarify?

I may strongly disagree with Grooveshark as a company, but that doesn't mean you aren't one of the only legitimate players with experience in delivering audio on the web. I am curious to hear more.