你以長度 30 秒的影片廣告成功放送了知名度廣告活動，現在你發現觀看過該廣告的目標對象具有再行銷價值，因此想向他們放送容易記憶的短片廣告。你該使用哪種影片廣告格式來達成這個目標？

Bumper ads are six-second, non-skippable video ads designed for maximum reach and memorability, making them ideal for remarketing to an audience that has already seen a longer ad. They are short, impactful, and effective for reinforcing a message. In-feed video ads appear within YouTube feeds and are not inherently short or non-skippable. Masthead ads are premium placements on the YouTube homepage, primarily for broad reach, not specifically for short, memorable remarketing. Non-skippable in-stream ads are longer (up to 15-20 seconds) and are not as concise as bumper ads for quick, memorable impressions.