下列哪種價值，經常用於定義以價值為準的成效評估策略？

Actual value" is the correct answer because value-based performance measurement strategies in advertising focus on the tangible, real-world returns generated by campaigns. This includes metrics like revenue, profit, or customer lifetime value, which directly reflect the actual contribution of advertising efforts. "Unique value" refers to what differentiates an offering, not its measurable impact. "Necessary value" implies a baseline requirement, not a performance metric. "Intrinsic value" relates to inherent worth, which is often subjective and not directly quantifiable for performance evaluation in an advertising context.