From the book by Charles Bloom

http://www.cbloom.com/poker/book.html

"So, that's our first key point - good players do not make their profit by making big hands. Often when a fish plays against a pro they feel like the pro is getting good hands all the time. Obviously a pro doesn't make big hands any more often than a beginner, but they make a lot more money. How do they do it? Poker pros make their money (compared to amateurs) on every single hand - including hands they lose! Your goal as a poker player is to A) win more pots, by making your opponents fold when they have the best hand, B) minimize your losses by folding when you're beat, or keeping the pot small with marginal hands, C) make the pot big when you have the best hand, that is win big pots, and D) have small statistical advantages all the time."