A conversion is a defined action that a campaign counts as a successful outcome, such as a signup, wallet connect, download, deposit, or purchase. Outcome-based platforms reward conversions rather than impressions, since conversions represent verified value delivered to the project.
What counts as a conversion is set per campaign, and the choice shapes everything downstream. A campaign that counts wallet connects will attract different participants than one that counts funded deposits, because the effort required to produce each is different. Projects that set the bar too low pay for traffic that never becomes anything.
Counting a conversion requires attribution connecting it back to whoever caused it, and verification confirming it actually happened. Both usually arrive through a postback from the destination product rather than being inferred, which is what separates a counted conversion from an assumed one.