i think duration is more revealing.
foobar says it would take 8 weeks, 2 days, 7 hours, 12 minutes, and 44.105 seconds to listen to my entire collection.
not including the 100gb of music i've not yet tagged...
naturally i have a lot of music i've never listened to. but i figure it's best to amass an impressive collection now, before things change and it becomes harder to obtain free music