After the sign up bonus, this is the bonus that is probably the easiest to get. One simply has to get more people to sign up with the casino using a casino provided referral code. You can simply sign up your friends and other colleagues for a simple bonus, or you can get them to make a real cash deposit and get extra bonuses. The more the number of players you refer, the bigger your bonus gets! One very attractive casino bonus for new players which often comes as a form of welcome bonus is…