I once worked on a redesign for a site, and one of the sections I worked on was the "photo gallery" section. I had a beautiful JavaScript-based photo gallery which had nice transitions between photos, it was pretty slick and nice and fast. It even degraded to full page-loads if you didn't have JavaScript enabled.<p>In the end, I had to take out my beautiful JavaScript-based gallery and present the "degraded" experience all the time because after it went live, pageviews dropped "dramatically" and the ad people didn't like that.<p>In retrospect, I probably could've just refreshed the ads via JavaScript when I transitioned to a different photo, but the potential drop in ad revenue meant I was having to work quickly...