Which advertising format is considered 'richer' and includes units like skins and sponsor bars?

Rich Media is the correct answer because this advertising format encompasses more interactive and engaging elements than traditional advertising forms. Rich Media ads can include dynamic features such as animations, video, audio, and interactive content, making them more appealing and capable of capturing user attention effectively. Units like skins and sponsor bars are specifically designed to enhance the user experience by integrating with the surrounding content and providing immersive advertising opportunities.

Standard Ads typically include basic display formats like banners, which lack the interactive elements found in Rich Media. Responsive Ads are designed to adjust their size and format based on the device being used, but they don't inherently possess the interactive richness associated with Rich Media. Native Ads aim to blend seamlessly with the platform's content but do not achieve the same level of engagement through multimedia features that characterize Rich Media. Thus, Rich Media stands out as the most versatile and engaging advertising format.