Play games
Choose the game that interests you and play itfor free.
Complete the quests
Every game has some quests for which you will receive Soul Gems.
Receive rewards
You can exchange your Soul Gems for Steam Wallet top-ups, game keys, CS:GO Skins and other rewards.
You can get SG by doing different kind of quests or by cliking the icon of SG in top of the screen. you can also watch adds for 1 SG permanently.