Online casinos paranoia about "casino bonus hunters" is forcing them to be very creative to wean the hunter away hurting all players with complicated bonus rules. One of the most recent creations are "phantom" or "sticky casino bonuses" - the equivalent of lucky chips in land and mortar casinos. The amount of the casino bonus is impossible to withdraw, it must remain on the casino player's account (as if it "has stuck" to it), until it is completely lost, or annulled on the first withdrawal of cash means (disappears like a phantom). A casino bonus is "sticky" if in the terms and conditions of the online casinos it is described as non-cashable or for wagering purposes only. The online casinos do not call the bonus "sticky". That's the players slang for a bonus that "sticks" with the casinos.
To make it simple: a casino player would have two accounts deposit and casino bonus account. Bonus account cannot be cashed in, but can be used for wagering purpose. Deposit account may only be cashed in once the balance of the casino bonus account is zero.
At first glance it may seem that these casino bonuses are completely useless for the players and there is little sense in such bonuses - you won't get your money back anyway, you won't get your winnings, you would only waste your precious time. But it is not completely true. If you win, then there is really no point in the casino bonus, but if you have lost, it may be of use to you. Without the casino bonus you have lost your $100 and that's it, bye-bye. But with the bonus, even if it is a "sticky casino bonus", it is still on your account, which can help you worm out of the situation, to wait out the negative trend.
However a possibility to win back "sticky casino bonus" is a bit less than 50% (for that you only need to bet the entire amount on the chances in roulette). In order to maximize profits out "sticky casino bonuses" a casino player has employ a high risk strategy "play-an-all-or-nothing game". Really, if you bet with small stakes, you will slowly and surely lose because of the negative mathematical expectations in the casino games, and the bonus will only prolong an agony, and won'thelp you to win. Indeed, since a player expects to lose anyway thanks to the build-in house edge, and due to the non-cashable terms of the bonus, where is the profit?
Professional players tent to wager sticky bonuses aggressively. Somebody bets the entire amount on chances, in the hope to double it. Even though it is not possible to cash out the bonus, professionals can use it to win money that can be cashed out. Just imagine, you stake all $200 on chances, with a probability of 49% you would win neat $200. With a probability of 51% you would lose your $100 and $100 of the bonus. That is to say, a stake has positive mathematical expectations for you $200*0,49-$100*0,51=$47.
The difference between cashable bonuses and sticky ones is that the closer you are to meeting the casino wagering requirements the less aggressively you should play your cashable bonus, it would be yours anyway. So why should you risk. Besides, conservative wagering of cashable bonuses would help to avoid big fluctuations of the hands results. With the non-cashable casino bonuses the profit comes from the fact that a player can wager with the casino's money and keep the winnings. Betting sticky bonuses aggressively would help to avoid "work hard" through the whole wagering requirements and get the results early. If number of big wins comes early, a player can always cut back the bets and "work hard" through the wagering requirements with smaller stakes to protect the winnings from that point on.
In summary, the aggressive casino games wagering requires a professional-level understanding of risk versus return as well as large enough bankroll to invest into the future winnings after a long losing trend. Also the strategy is complicates by such things as restricted casino games for wagering, the casino's betting limits, the wagering requirements for the bonus, the house edge for the particular game.