Sitting out AT Texas Hold'em :

Most of the players marked as 'away' for the entire game usually blind out shortly after the 1 hour mark, and it is very rare they ever make any money off it (especially if they paid to enter). In a way it makes a shorthanded table (increasing your playable hands) and gives you an opportunity to steal some blinds.

My favorite tactic is to catch those trying to steal the 'away' blinds who raise preflop with a really poor hand and forcing them out by reraising (only works when you have a decent hand) instead of just calling to see the flops. By doing this, you win the extra blinds and often some extra chips from the guys trying to steal the blinds with nothing.
OK. I just played a sng tourney and 1 player sat out until 7 were gone. He was left with a little over 800 in chips, was in the money, and came back and won the tourney. How about that one. Didn't play one hand until he was in top 3! Oh well. Takes all kinds I suppose.

Before you say he paid for it, and he gave up his blinds, let me say this. Part of this game, if not the biggest part, is not making any mistakes. Making the right decisions. Limit your plays, protect your stack and don't chase, etc. Sitting out until you're in the money reduces those variables of risk. When you come back, you still have enough of a stack, although it is much less, depending upon when you decide to play like a frigging poker player.

Yes, the player can sit in the game and accomplish the same result by folding every hand, but these lamebrains are cowards in as much they figure they may not want to fold a good hand and decide to play it and lose by some other fruitcake that plays slop and hit's their hand.

For some, sitting out is part of their strategy. I say, if you can sit on a toilet as long as you can sit out in a game, then you should go see a doctor.
Many players play too many hands - and thus lose money. Playing tight on the first rounds can help one stay alive a lot longer. The blinds are so small that the chance to win big are rather slim unless one meet another
player with a big hand - and then the chance to not win the hand are rather large. Waiting for a very good hand are often better.
Some people actually sit out while still watching their cards. You will notice they come back in on the BB or when they have a good hand. They are tryng to be deceptive. In my opinion they are wasting their energy.
Some people dont realize all you need to do is hit bet and the away person will fold. other times they are just not paying that close of attention because of playing multiple tables. the away player is not exactly easy money when the player is watching his every hand and wait until someone tries to steal his blinds.. suddenly bam he is there.. more than likely with the better hand. beware of the lurking away player.