Let's say for a typical 4-minute song. I understand that it can vary greatly depending on how it was recorded, but if you add up all of the files sent for a 4-minute song, what's the ballpark MB size that you're generally looking at?
Also, how do authors typically receive the files? Burned on a disc (CD? DVD?) and sent through the mail or sent via a file transfer protocol (FTP) to be stored on a website? I imagine e-mail attachment is not a practical method.