Incremental conversions are additional outcomes caused by advertising compared with what would have happened without it.
How much was added, rather than who gets credit?
Illustrative example: randomly assign two comparable groups of 1,000 people. The advertised group makes 60 purchases and the control makes 50. With a valid design and measurement, the difference can help estimate added purchases. Statistical uncertainty still matters; an arbitrary difference between groups is not causal evidence.
Design a comparison before reading the result
Holdout groups and geographic experiments are common approaches. Define outcomes, duration and assignment in advance, and examine cross-group exposure, promotions and seasonal differences. A before-and-after comparison alone can misattribute other changes. Google Conversion Lift is one tool, but is not available to every account.
AI visibility is not an incremental order count
More AI mentions, brand searches or reported ROAS do not by themselves establish added demand. Incremental ROAS divides incremental conversion value by ad spend; revenue-based value is not profit. If AI placements cannot be isolated, a campaign-level result does not identify their individual causal contribution.
Sources
Definitions and source documents checked on 2026-11-07. Examples marked as illustrative are not measured results.