An advertiser is comparing view-through rates between in-stream and Shorts within a Video view campaign. Why might these numbers look different?

In-stream and Shorts ads are fundamentally different formats within Google Ads, each with unique audience behaviors and viewing contexts. In-stream ads typically appear before, during, or after video content on YouTube and Google Video Partners, often viewed in a more focused, longer-form consumption setting. Shorts ads, conversely, are designed for short-form, vertical video content on YouTube Shorts, where users rapidly scroll through content. Because of these distinct user experiences and platform designs, their view-through rates will naturally differ and should be analyzed independently to accurately assess performance for each format. "In-stream ads are always longer than Shorts ads" is incorrect; while often true, ad length isn't the sole differentiator for view-through rates. "Shorts ads are designed for quick engagement, while in-stream formats focus on longer watch times" is a contributing factor but doesn't fully explain why independent evaluation is necessary. "Unlike in-stream ads, Shorts ads are only available on CTV" is factually incorrect; Shorts are primarily a mobile experience.