As the Christmas trading season takes force online, retailers are being urged to ensure their web sites don’t annoy visitors. So what’s  the most annoying thing you can do? Add a pop-up advert. According to research from Taylor Nelson, 84% of people find pop-ups “extremely annoying”. Dead links are also a source of significant annoyance as is content that is out of date, slow loading pages and a lack of contact information. These are things that many web sites appear not to worry about, instead focusing their efforts on good design. But the Taylor Nelson study shows that poor design is one of the least annoying things of all. In other words, what this study shows is that you need to get the content right,  not the design.