good design should never make you stop
I recently visited the Canadian Ikea website and was utterly flabbergasted at what greeted me: a 15-second flash video that disables the search box and main navigation. I'll admit the concept is cool and the execution is excellent. But the user experience is just awful.
Imagine you're a busy shopper. You have a particular product need and you want to find the right solution as quickly as possible. So you go to the Ikea website... and for a full 15 seconds, the main navigation and search box are frozen. There's no way to turn the video off.
Worse yet, the site doesn't remember it's already shown you the video. It plays every time you visit the page, regardless of whether you're starting a new session or have simply navigated back to the Home page. You're stuck: you have to sit through the entire video again, with no way to stop it, and no way to search or navigate the site.
Did Ikea actually test this page with real users before implementing it? Though I can imagine a subset of the population might think it's very cool, I find it hard to believe that a large percentage of users wouldn't have protested loudly at being stalled in such an aggressive and persistent manner.
ed.: Now with video, thanks to John Hossack