The audience that converts cheapest and the audience worth expanding are rarely the same list.

A conversion event is not a customer

Lookalike and interest models are trained on whatever the pixel confirmed: a form fill, an add-to-cart, a checkout. An account trained that way finds more of whatever converts cheapest — leads a sales team never works, orders that come back as refunds inside the month. The network is not wrong about any of it; it is optimising against the only outcome anyone handed it.

Quality joined back to the click

The click or lead identifier the platform issued travels with the conversion into the CRM record and onto the line your finance system later settled. Conversions that never join are reported as unmatched rather than quietly dropped, because a climbing unmatched rate is usually a tracking fault and not a quality signal. Segment builds, value uploads, suppression lists and expansion seeds all read from that one joined table.

Budget follows margin, inside limits

Audiences rank on margin per customer and refund rate rather than conversion volume, so budget moves toward cohorts that still hold up once refunds have settled. Every audience action is written by the action service under the Campaign Constitution: which exclusions it may set, which value uploads it may send, which changes wait for an approval. Each write is logged with its evidence and can be reversed to the state it replaced.