Stephen Konig, Google Chrome's Product Manager, wrote a post on the Chrome blog, Chromium, advocating for the WebP image format. According to the post, WebP compresses better than formats like JPEG and PNG. And as Konig points out, 60 percent of the data that makes up a web page is from images.
Konig wrote that switching to WebP "translates directly into less bandwidth consumption, decreased latency, faster page loads, better battery consumption on mobile, and overall happier users." He uses the Chrome Web Store as an example. The store has many large images and tiles on its homepage, "making it a very heavyweight page."
The Chrome Web Store managed to reduce their image sizes by an average of 30%, without any noticeable difference in quality (here are sample images in JPEG at 32KB and WebP at 8.3KB). Konig said that this difference adds up to "several terabytes of savings every day."