Every time you spin in ANY slot, you get the fireball points which are used for the World Slots League ranking system. You earn more fireball points with higher bets and x2 points playing in the High roller club.
Once the season ends (which is indicated in the WSL), the more points you have, the higher chance you qualify for a higher division.  Higher Divisions increase their store purchase and scratcher winnings.
 
WSL Divisions
  • Immortal
    • Scratch and Win x5 - x100
    • Store Purchases   + 50%
    •  Legendary Stamp  x3
  • Legend I
    • Scratch and Win x4 - x75
    • Store Purchases  +40%
    • Legendary Stamp  x2
  • Legend II
    • Scratch and Win x4 - x 50
    • Store Purchases  +30%
    • Legendary Stamp  x1
  • Master I
    • Scratch and Win x3 - x 40
    • Store Purchases  +20%
    • Legendary Stamp  x6
  • Master II
    •  Scratch and Win x3 - x 30
    • Store Purchases  +10%
    • Legendary Stamp  x5
  • Expert I
    • Scratch and Win x3 - x 20
    • Legendary Stamp  x4
  • Expert II
    •  Scratch and Win x3 - x 16
    • Legendary Stamp x3
  • Pro I
    • Scratch and Win x2 - x 14
    • Legendary Stamp  x2
  • Pro II
    • Scratch and Win x2 - x 12
    • Legendary Stamp  x1
  • Rookie   
    • Scratch and Win x1 - x 10