It would be great if Spotify were to support ".wma" (Windows Media Audio) files. I'm something of an audiophile, and I found that .wma lossless ripping resulted in a sound quality superior to other compressed audio file formats, especially .mp3 files. In fact, if Spotify supported .wma files, I would be inclined to buy premium, especially if they were only supported for premium users.
This idea has been submitted more than 1 year ago but unfortunately hasn't gained enough kudos during that time (10 kudos/year). In order to keep an overview of the active ideas in this forum, this idea will be closed for now. Note that this does not mean the idea has been declined by Spotify.
Please feel free to re-post this idea if you still feel you want this implemented. With a little change in presentation, maybe this time it will gain the necessary support from the community.