As the marketer for TravelTheWorld.com, the user experience for the site is Harper's responsibility. They enjoy creating rich, impressive content that creates a welcoming environment for users. But the slow performance of the site frustrates them. What's a factor that's probably slowing down the performance of the website?

Large video files significantly increase page load times, especially if they autoplay or are not optimized for web delivery. Harper's focus on "rich, impressive content" likely includes high-quality videos, which, while visually appealing, can be a major culprit for slow website performance. HTML is a lightweight markup language and generally doesn't cause performance issues unless the structure is excessively complex, which isn't indicated here. While coding errors can slow down a site, the prompt specifically mentions "rich, impressive content" as Harper's focus, making large media files a more direct and probable cause. Localization, the process of adapting content for different regions, doesn't inherently slow down a website's performance; it's about content relevance, not file size or processing.