So I used google (the search function here is a bit lacking for my tastes) to see if I could find a previous topic on this but nothing came up.

Anyway, you guys might be familiar with purchasable soundtracks. A good example is "the Binding of Isaac", you can buy the game but you can also buy the soundtrack to download all in-game songs.
And yes, if you dig deep in most game files you might be able to find the soundtrack themselves, yet people still buy them, even if they can get them for free through the use of torrents.

My proposition was adding "Spiral Knights : the soundtrack" to the steam store (or to the Spiral Knights in-game store). It contains every single Spiral Knights song to download on your PC. Sales statistics show that even though you could get these for free if you tried, the company selling them usually still makes a nice profit. Also, the songs in Spiral Knights are pretty cool and I wouldn't mind relistening them in the background of something I'm doing when I'm not playing Spiral Knights.

Of course, to spike sales, OOO could add an accesory item, like a headset for your helmet, or a pocket radio for your armour, to show your love for their songs, which will be obtained when purchasing the soundtrack.