I dont think you need to upgrade the account, I went on Pandora's site and it said its compatible with Sprint but only certain phones. This doesnt make sense to me. I did enter in my cell phone number and it would send me a text message, basically that text message was a link to
www.pandora.com/sprint and once you go there the browser says phone not supported.
If someone was able to get this to work it would be awesome.