Almost all casino websites has a Loyalty/VIP Club scheme. You accumulate points while you play and you can get bonuses in return for the points you have. Your points will increase the more you play, the higher the points, the better the conversion rate.
Make sure you check the terms and conditions of the casino you are playing at because most times you will not be able to withdraw your bonus or it will be deducted from your overall winning
Bonuses have a lot of advantages but it has its downsides also.Online casino gaming sites have various very sensitive techniques to detect bonus abuse which is also called bonus whoring.If you are suspected of bonus abuse, your online players account can get blocked.
All in all, keep it in your mind that online casino is mainly for entertainment purpose and you should not see it as a day job or depend on it as a means of livelihood.It is solely to catch fun and have a good time.