本研究包含兩項研究主題，深入分析贈品促銷深度的轉折現象以及對產品知覺價值的影響效果。贈品促銷深度為贈品價格相當於主產品價格的百分比。研究主題一欲找出贈品促銷深度對贈品價格合理性影響的轉折點，研究結果：品牌形象高時，贈品促銷深度轉折點為50%，品牌形象低時，轉折點往下修正成40%或20%。研究主題二進一步探討轉折前的合理贈品促銷深度、轉折後的誇張贈品促銷深度對產品知覺價值的影響效果。研究結果：合理深度下，深度愈深，整組產品知覺價值愈高，但誇張深度下，深度愈深，整組產品知覺價值愈低；其次，主產品與贈品品牌形象皆產生干擾效果，亦即品牌形象高時，最高與最低深度在整組產品知覺價值上的差異，會大於品牌形象低時的差異。
Two themes in this research were arranged to investigate effects of gift promotion depth. Gift promotion depth was defined as a percentage of gift price by main product price. The first theme proposed that there is a turning point in promotion depth and the turning point was fluctuant in accordance with brand image. If the brand image was high, the turning point was 50% Fhowever, if the brand image was low, the turning point was downward to 40% under low brand image of main product and downward to 20% under low brand image of gift. Based on these findings, promotion depth was divided into two categories-reasonable (depth before turning point) and exaggerated (depth after turning point) promotion depth. The second research theme focused on the effect of reasonable or exaggerated promotion depth and its interaction with brand image of main product and gift. Findings included three points. First, the deeper the reasonable promotion depth was, the higher the perceived value of product bundle was (eg. positive relationship). However, in the range of exaggerated promotion depth, negative relationship was exhibited. In addition, brand image of main product and gift did show significant moderating effect. That is, the difference of perceived value of product bundle between the highest and lowest depth under the situation of high brand image was larger than that under the situation of low brand image.
