While I don't gamble online (or elsewhere now for quite awhile), my original spark of k5.fame involved gambling, and this piece rings very true to me.
My card-counting friend X tried a stint at poker and found in RL pretty much what odano reports here. His version was that, at any table, you can make money as long as you aren't the "donator." People who play a lot of RL poker are pretty much a small insular group who know each other by sight, and X found that too often he was the donator.
Do not worry about armies of poker shark bots. Blackjack has been solved for more than twenty years, but poker is still considered hard by game theorists. Your biggest threat even online is the vast pattern-recognition capability of your human opponents.
Although you can provide yourself some mechanical helpers, such as automated probability guides, much of poker play can't be automated without judging what other people will do. If you are consistent your style can be made and you will lose, even at the PC where you have the perfect glass "poker face." You must vary your style while gauging the styles of the other players. It is not probability theory but spotting exploitable patterns in your opponents' play that will get you the big edge. If you always bluff or never bluff your style will quickly be made; you win when nobody can tell whether you're bluffing.
Online poker is the one form of online gambling I would be tempted to try, if I was any good at poker. There is little reason for the online casino to electronically cheat you and much opportunity for them to be caught if they try. It's like the tournaments I used to play in; since you're playing against other players, not the house, they have no incentive to rig the game. They get their rake no matter who wins. By contrast, they could easily rack up the house edge at a game like Blackjack or Roulette as high as they want and nobody would be the wiser.
The nature of poker would even make it pretty hard to rig with shill players working for the house. By the time your rigging bot could tell what cards to magically produce, very often they'd already be dealt to some human player.
I have also been told by big wheel RL players that online poker has changed the face of their sport. Last year the World Championship was won not by someone who played poker since their wee years, but by a guy who learned to play online. Online you can get a great deal of play in in a short time, racking up the kind of experience that takes a lifetime of pick-up and casino games. Then when you enter the room full of sharks you have an advantage; most of them are known by at least some of the others, and you may have even seen some of them play on TV; but to them you are a total mystery until they've played against you for awhile.
It's not for everybody; you have to be comfortable with probability math and calm. (The #1 exploitable predictable style of bad play is being too eager to play bad hands. The hardest thing to learn is to let go when you are dealt lemons.) But the author is right, there is a steady trickle of cash waiting to be tapped for someone who is willing to put up the effort and learn the game.
I am become Death, Destroyer of Worlds -- J. Robert Oppenheimer