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 have been three days since that website not updating their Drop Key. Drop Key is like having chance to win a game key. You were given 20 chances to win. I used to win daily and it have 10$ great game. The only requirement is you need atleast do one purchase on the website.