As the article states the first three months (trial period) is free after you will pay 9.95 a month IIRC.
And if it's anything like cable TV pricing, after a year it will go up to 19.95 a month .
Okay, let's break that down. Say you get folks who stream 2 hours/day. Average song is 5 minutes. 120/5 is 24. So 24 songs a day for a total of 720 songs/month. Cost per song is $0.0138 for the consumer. Now get someone who streams 4 hours a day, cost per song drops to $0.0069. Someone who streams 8 hours a day pays only $0.00345/song. So, yeah, Apple is making bank on these guys, even when someone is streaming 8 hours/day. Meet the new boss, same as the old boss.