What costs belong in an organic acquisition experiment?

Include the costs that change with the experiment: creative production, account operations, publishing, data collection and the team effort required to review results. Keep fixed platform costs separate when that distinction helps the decision.

Then relate the relevant cost to verified outcomes with an appropriate observation window. A campaign can be worthwhile before its long-term economics are fully known, but “organic” is not a cost model. Make the assumptions visible so the next expansion decision can be compared with the previous one.