re: Poker & Average income for TAG/LAG
Well, when you have an approx. hourly rate, you'll know how you should expect to win on average if you sit at the table for 4:30 hours. Very few people will set hands goal for a session, but many will set time goals so it becomes interesting for them to compare and know how they fared.
But it's true that unless you always play the same game (LIVE, where you can't count hands), you're better off figuring your BB/100 hands.