研究目的：網路口碑已被証實能有效影響銷售量，但口碑對不同價格／品牌的商品是否有一致的影響力，又其影響力是否隨時間增減仍未知，本研究以智慧型手機為例探討價格及品牌對口碑與銷售量間關係在不同銷售時期的影響。研究設計／方法：分析四款不同價格和品牌手機（高價／低價x強品牌／弱品牌）在購物網站Tmall.com的口碑及銷售資料以驗證假說。研究結果：重要發現：（1）口碑數量顯著影響銷售量；（2）口碑數量多寡對銷售量的影響會因品牌強弱而有差異，對強品牌的影響大於弱品牌；（3）口碑對銷售量的影響並非都隨時間過去而降低。研究限制／啟發：本研究主要聚焦於口碑對銷售量的影響力，未涵蓋包括消費者需求、市場競爭等可能因素。理論／實務／社會意涵：企業資源有限，本研究結果能協助企業在不同銷售時期訂定差異化行銷策略，讓資源運用效益極大化。創見／價值：本研究為品牌研究提供口碑影響力動態分析的重要創見。

Purpose -Although word-of-mouth has been demonstrated to significantly affect sales, its impact on different types of products over time remains unknown. To fill this gap, this study examines the influence of product prices and brand on the relationship between word-of-mouth (WOM) and sales over time through a case study on four types of smartphones (high/low prices for strong/weak brands). Design/methodology/approach - Weekly sales data and online WOM of these smartphones were collected from the major Chinese shopping website Tmall.com for six months. This investigation is conducted within the frameworks of signaling theory, perceived risk theory, and uncertainty reduction theory. Findings - Results show that the influence of word-of-mouth on the four types of product sales vary across different sales periods. With the rapid growth in the Asia-Pacific market and the number of global smartphone users, the present study provides empirical evidence for the impact of WOM on smartphone sales in the Chinese market. Research limitations/implications - This study only inspects four models of smartphones with different brands and prices in the Chinese market. Future studies may include smartphones in different price segments for a more comprehensive analysis. Practical implications/Social implications - The results provide important references for smartphone companies to develop marketing strategies in different sales periods and offers a conceptual framework for future research. Originality/value -This paper provides valuable insight into the temporal dynamics and effects of WOM on smartphone sales and offers a foundation for future product branding research.