I know how you can earn quadrillions of coins in Jackpot World.
Before I discovered this trick my coin is about 1 trillion and I barely win any, I also spent alot just to get to trillion coins.
Now I already reached around 10 quadrillion coins and now I'm at level 30000. Easily become rank 1 on every leaderboard in jackpot world.
Not just coins, also jewels around 10 to 20k, 10 thousands of level and thousand of stamps.