The daily Bonus Club, is a feature you can unlock via in game purchase(s) Once you become a member you are in the club for 30 days. Once this time expires you will have to repurchase an appropriate in game pack with the membership to renew membership. There is 3 levels of membership each providing slightly different rewards.
Challenger level is the lowest level of membership. It provides 300 Gold for every day you log in as well as Login streak bonuses, potentially giving you up to 15000 Gold over the month.
Veteran Level is the mid level membership that provides 400 Gold for every day you log in as well as Login streak bonuses. It also has Daily Bonus Club goodies in all Sales and Challenges. You can potentially get up to 22000 Gold over the month.
Elite level is the top level membership. It provides 500 Gold for every day you log in allowing you to gain up to 30000 Gold during the month with the Login streak bonuses. In addition there is daily gifts that come via the mail contain Speed ups, resources, restricted files and other bonuses and like the veteran level there is Daily Bonus Club goodies in all Sales and Challenges. You also gain exclusive VIP bonuses which add to your current VIP stats, the higher your VIP prestige level, the more the extra improvements you’ll gain.
There is also an Elite plus membership which lasts for 7 days, this provides upgraded rewards to everything offered in the Elite membership, once your Elite plus expires you continue your elite membership.
The Daily Bonus Club is a feature that is well worth acquiring, The Elite membership is easily the best membership to have and the additional benefits received daily can really help to grow your account and give you the advantage over your enemies not members of the club!!