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.
I was looking around this site and saw even knifes selling for 70000 gems. I would just like to know how if someone has bought a knife here and how did you get that much gems