Casino bonus hunting refers to a method used by seasoned players to mine money from bonuses given by most online casinos. It is not a short-term plan and requires patience. Many have been, and continue to be successful in this hunt. Bonus hunting goes by different names such as bonus whoring or bonus abusing. Recently I found this nice research on bonus hunting so I have decided to summarize its outcomes for you.

How it worked then, and how it works now
A while back, bonus hunting was a piece of cake. Online Casinos gave huge bonuses. The wagers were low and they had no restrictions on the games allowed. This implied that the players could utilize the bonuses and hope that their expected values would yield fruit in the end. This was how it worked:

If a player, for example,deposited $100 a got additional $200  as a bonus with WR of 25x, he washoping to meetthe WR by betting on a blackjackgame with an RTP of 99%. This means the casino hada 1% advantage, so the player was statistically loosing1% from every bet. Thus the bonus value the player couldexpect was $200* (100%-25*1%) =$150. That was his expected profit from playing the bonus.

These days, casinos are much smarter. They do not give bonuses that have such easy profit clearance. However players can still make money using casino bonuses. Bonus hunting premises on high volatility and requires a lot of money and skill. It also requires you to have a lot of spare time and the strength of character to withstand losing. It works like this:

1. Make your deposit and receive a bonus 
2. Be aggressive while playing. The slot you settle for should have a very high variance. Play to win or lose everything
3. In the event you lose all, you have to leave and go to another casino. If you win, then you have some amount to cushion you and to allow you to afford your WR bonus and the eventual cashout which covers previous losses and leaves you with the profit.
You have to keep doing this many times for it to make any profit. It is possible to win the first time or your lucky streak may hit after 50 tries.

Bonus hunting using high Volatility
Bonus hunting using high volatility works like this:
1. Deposit an amount, say $100 and get some amount to play with, like $200. The WR could be for example 32x$200
2. Play very aggressively and make sure you either lose everything quickly, or the bonus gets multiplied several times, for example, let’s assume you end up with$6,000 or more
3. Don’t stop playing as this amount will comfortably cushion your WR
It is very important that you learn how to estimate a slot’s volatility and know its RTP.
The producer of the slot publishes the RTP.
Have a look at the pay table. Look at how much all the major symbols full line pay
Read all the rules, regulations and about any special features
Find out what the maximal win entails in the 1st spin, and how to get it
Count how frequent the major symbols appear on the reels and try to calculate the winning combinations frequencies
Check the frequencies of the game features
Play in demo mode for long periods and monitor the rounds that win.

You will be surprised that the best slots are high or medium variance and an RTP that exceeds 96%.  The high volatility required for aggressive play can be achieved by several means. The most straightforward to use higher bets but be aware that casinos usually restrict maximal bet when playing with bonus. Less straightforward is to choose high volatility slot or decrease the number of slots winlines. As many casinos restrict maximal bet as absolute number simply taking a lower bonus may also do the trick.