贈品促銷廣告中常出現贈品價格，使得贈品促銷也參雜著類似價格促銷的訊息，因而贈品促銷與價格促銷兩者間的藩籬日趨模糊。在此情況下，是否贈品促銷的價格訊息會影響消費者對贈品促銷組合的評價？本研究著眼於贈品價格相當於主產品價格的百分比(簡稱為贈品促銷深度)，以三項實驗對贈品促銷價格訊息的內在評估機制進行探討。實驗一發現贈品促銷深度與產品態度評價間呈現曲線關係。實驗二驗證贈品促銷深度的內在評估過程，發現贈品促銷深度高於消費者內在參考深度時，兩者差距愈大，消費者對贈品促銷活動合理
性評價會愈負面。實驗三進一步發現，消費者傾向採用範圍理論而非適應水準理論的模式，進行內在參考深度的比較評估。

Recently, price information, especially price of the gift, commonly shows up in gift promotion. Does the price information affect the evaluation of gift promotion? The research focuses on the gift promotion depth, defined as the percentage of gift price by main product price, and develops three experiments to discuss the internal comparison mechanism of the gift promotion depth. Experiment 1 investigates the effect of gift promotion depth and finds that the relationship between gift promotion depth and consumer’s attitude toward product and gift is curve-type. Experiment 2 discusses the inference of gift promotion depth on the reasonableness perception. As the distance between gift promotion depth and internal reference depth becomes larger, the distance has a negative effect on
consumers’ reasonableness perception of gift promotion. Experiment 3 further analyzes the internal comparison process and would like to confirm whether this process is based on adaptation-level theory or range theory. Results show that range theory is more adequate to apply in the context of gift promotion. Through the three studies, the internal comparison mechanism of gift promotion depth and the effect of gift promotion are both clarified.