Free Gems And Credits
On the Android side, you can sign up to become a VIP and score 50 or 260 Credits for choosing Silver or Gold, respectively.
For both iOS and Android, you have the option of signing up for and/or downloading services and Apps, whereupon which Glu will reward you with Gems or Credits. The list of activities include, but are not limited to:
Sign Up For Netflix!: 680 Gems
Watch Big Fish Casino! Video: 1 Gem
Get the Discover More Card: 1,632 Gems
Sign Up For Gamefly.com: 816 Gems
Buy Gourmet Chocolate, Dipped Strawberries: 462 Gems