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.
It is currently 4 percent, I think I remember getting it for a better price like 7 percent discount but I don't remember it and can't see the logs for my older orders because a lot of time passed and gems gained since.