The rake
Online poker rooms all generate revenue via the rake. The rake is paid by the players, and it is taken off every pot as a set percentage. The industry standard is 5% up to a maximum of $3 (if you’re a high stakes player you’ll pay less than 5% because of this setup), but every poker room has its own set of rules concerning the rake. Some do not take rake at all on micro-limits, others feature reduced rake on certain limits etc.
There is a huge misconception among rookie players that the rake is paid by the winner, so as long as one doesn’t win, he won’t pay any rake. The truth of the matter is that the rake is taken off the pot before it’s awarded to the winner, therefore it is not the winner who pays the rake but the pot, which is a separate entity at the table. Since the pot is made up of the individual contributions of all the active players around the table, we can conclude that the rake is in fact paid by each and every one of those who contributes money to the pot.
Some poker rooms use the dealt rake method to calculate player contributions. The dealt rake method awards rake contribution to all those who were dealt in, regardless of whether or not they contributed money to the pot. This method provides a nice advantage to tight-passive players, while the aggressive loose guys get roped and end up generating poker points and rakeback for others.
The contributed rake method calculates every player’s rake contribution as a direct function of the amount of money they contributed to the pot. This rake calculation method provides advantage to loose-aggressive players, and gives no credit where none is due.