规划品牌建设推广活动时，漏斗中的三个阶段 (认知度、考虑、转化) 都很重要。

This statement is correct because a successful brand-building campaign requires a holistic approach that addresses customers at every stage of their journey. The Awareness stage introduces the brand to potential customers, building recognition. The Consideration stage engages these potential customers, providing information and value to foster interest and preference. Finally, the Conversion stage prompts desired actions, such as purchases or sign-ups. Neglecting any of these stages would create a gap in the customer journey, leading to lost opportunities and an inefficient campaign. For example, focusing only on Awareness might generate interest but fail to convert it into sales, while focusing only on Conversion without prior awareness or consideration would likely yield poor results.