Why isn't it free? The Sonos app for the iPhone is.
The iPhone application is written by Sonos themselves so they make their money on their hardware, not the iPhone app. Phonos was developed entirely independently from Sonos, Inc.
What about supporting My Favorite Music Service?
Please vote for your request on our Facebook page and we'll see what people want.
Why does it need a PC application too?
It doesn't any more! There were restrictions in the networking abilities of Windows Phone 7 so the 1.0 version could not
communicate with the Sonos hardware directly. Instead it communicated with the PC software, and the PC communicated with the Sonos hardware.
These restrictions were removed in Windows Phone 7.5 so the 2.0 version of Phonos no longer requires the PC software.