At what point are you just a gambler?

[PShabi]

I used to be right with you guys. Limit Hold 'Em isn't gambling, it's an investment.

However, I'm about 1/2 way through with Sklansky's Small Stakes Hold 'Em, and this is what he has to say on the matter:

"As can be seen, poker is gambling. Anyone who says it's not or states that when he plays he doesn't gamble, does not understand poker as well as he should. Poker is gambling because your outcomes, for the most part, are not certain."

He later says, "But what sets poker apart from many other gambling games is that your expectation can be positive. You achieve this mainly by exploiting the errors that your opponents make because the money comes from them."

Makes sense to me.