Belated Grammys Analysis

Actually, this raises more questions than answers for me. Nevertheless, it's a Grammys first:

Indies Win 50% Of This Year's Grammy Awards

Independent artists and labels had a banner year at the 2009 Grammy Awards winning 56 of the 110 awards given or just over 50% of the total prizes.

I'm still trying to figure out exactly what this means. First, how do we define an "indie"? Then, what does this signify?