Most poker rooms match your first deposit with an additional amount up to a certain limit. A bonus offer that states "50% deposit match up to $200" means that you get an additional 50% on top of your first deposit, i.e., to get the maximum $200, you have to deposit $400. Before the bonus is credited to your account and made available for withdrawal, you also have to play for a while on the site until the wagering requirements are met.
Some poker rooms require that you play a certain amount of raked hands per bonus dollar before the bonus is paid out. A raked hand is usually defined as a hand that reaches the flop and from which a fee (rake) is taken, and you have been dealt cards in the hand. Other sites use player points, which are awarded when you play in any real-money ring game or tournament, and can be exchanged for cash little by little - or as a lump sum - once you have reached the necessary amount.
When looking for the best poker bonus, you have to factor in the size of the bonus, the deposit match percentage, and the wagering requirements.
