Which IAB Rising Star Ad format is characterized by its ability to expand and engage users?

The Pushdown ad format stands out due to its unique design, which allows it to expand upon interaction, thereby enhancing user engagement. Initially, the advertisement appears in a minimized form, which can grab users' attention without overwhelming them. When users choose to engage by clicking or tapping on the ad, it expands to show more content, images, or calls to action. This interactive element is key to its effectiveness, as it encourages users to explore the ad further, leading to higher engagement rates compared to static formats. The ability to expand not only captures interest but also provides advertisers with an opportunity to deliver a richer and more immersive experience, effectively driving user interaction and engagement.

In contrast, other formats like the Billboard and Portrait have their own unique characteristics, focusing on visual prominence and mobile device compatibility, respectively, but they do not inherently include the interactive expansion feature that defines the Pushdown format. The Slider format, typically known for its ability to present a series of ads or content sequentially, does not emphasize user-initiated expansion in the same way that the Pushdown does, thereby lacking the same level of engagement opportunities.