In almost all poker rooms - live or online - the house will keep a small share of each pot. This cut is called the rake, and is the house's way of getting paid.
Usually at brick and mortar casinos you won't ever see any of this money again, unless you are super lucky and win a nice promotion like a jackpot.
However, on many online poker sites, the site will refund some of this rake to you, as a reward for your play. It's an incentive for you to keep playing there. This is rakeback, and it can have a big impact on your bottom line and on choosing where you want to play.
Rakeback isn't the only factor you should consider when choosing a site, but it is an important one. Different sites have different rakeback percentages, as well as other bonuses and promos that can
boost your bankroll. I'll help you compare everything so we can find the best site for you.
BigBadBabar - USA online poker, rakeback, resources