rebuys..add ons.. educate yourselves.. :)

There are two schools of thought concerning rebuys - some players prefer a high buyin with few rebuys, others prefer a low buyin with abundant rebuys. The play of your game will be affected by whichever method you use. Players will play conservatively (tight) if they know that they cannot rebuy and will play riskier (loose) if they know that they can rebuy if they go broke.

more info here