The Medium Rectangle display unit keeps viewers engaged as they scroll and explore content on which pages?

The Medium Rectangle display unit is strategically placed on Directory pages (like the "Browse" page) because these are where viewers actively explore and discover new content. As users scroll through various categories and streams, the Medium Rectangle provides a prominent, yet non-intrusive, opportunity to capture their attention and encourage engagement with an ad. Category pages (e.g., "Just Chatting") are a type of directory page, but "Directory pages" is the more encompassing and accurate answer. The Twitch.tv homepage is primarily for featured content and personalized recommendations, not extensive browsing. Channel pages are dedicated to a specific streamer's content, where ad units like the video player ad are more common.