When other players spend credits on paid turns in a world you published, you earn a share of those credits. Payouts are deposited to your account balance automatically each night.
Only paid turns by other players count. Free daily turns are excluded, and your own plays in your own worlds don't generate revenue.
Worlds that support immersive mode earn a higher share: 15% of paid turns by other players, up from the standard 10%. A world qualifies once most of its cast has sprite art (add sprites to your characters in the world editor). The bonus is based on the world supporting immersive mode, not on how each player chooses to view it.
Open your credit history (tap your credit balance, then view history). Revenue share payouts appear as "Creator Revenue" entries, showing how many turns were played and how many credits you earned for each world.