While the amount of money the house rakes from each pot is pretty small, because of the speed on online games the gross amount raked is pretty incredible. Fortunately, there is a whole world of players to contribute. Even though some of the worst players get chewed up too quickly, never to return, overall the rake is very favorable for winning players, especially since there is no tipping.
Some Conclusions
In casino poker, showing down the best hand is only one way a winning player makes money. The same holds true online, but the logistical ways a thoughtful player increases his or her win rate are mostly quite different. When playing AK against your opponent's J9, you aren't just sending one hand value against another. Players who only earn the value of the hand strength of the AK over the J9 will fall well behind the much more successful players who do the logistical groundwork of lobby monitoring, player notes and the rest. Hand value profit is only the tip of the iceberg.
Playing winning online poker is the science, craft and art of mastering things most players don't even think about.