Each day you sign into Zone Online Casino, you get some free Coins. These Coins are added to each Zone Online Casino account when first signing in each day.
The Daily Spin coins increase in value each day you log in consecutively. The reward grows for signing in every day, so if you miss a day, the bonus will drop but will start growing again if you keep signing in.
Up to five Daily Scratch Ticket Coins can also be awarded to you by your friends. Be sure to return the favor if they send you Tickets! Scratch Tickets are free for everyone, so it never hurts to send them.
Charms boost your winning wagers as you play. Standard Charms cost between 5 Gems and 500 Gems. The exact Charms you can buy rotate every few minutes (see the timer in the upper left?)
Charms purchased in the Charm Shop are known as Standard Charms. Unlike Party Favor Charms, these are just for you. Also unlike Party Favors, they can be recharged after they are used up. The value of each Charm is based on its Gem cost. For example, every Charm that costs 25 Gems is worth very close to every other Charm that costs 25 Gems. A Charm that costs 100 Gems is very close to 4x as valuable as one that costs 25 Gems.
Rare Charms - Each time you purchase a Standard Charm, you might get the Rare version. The rare versions have a different name, look a bit more fancy, and they pay out a bit more Coins than the normal versions. The more you spend on a Charm, the higher the chance it'll be rare. 5 Gem Charms are seldom rare, while buying 100 and 500 Gems gets you far better odds for a rare.
Also check out How Do Charms Work?