How long do you have to snag your reader’s attention before you lose them? Say it with me: ten seconds or less. We’ve had this drilled into our heads, and great designers know what keeps people reading and what doesn’t. But what hasn’t been learned nearly so well is that your customer’s online attention is not only short, but also very narrow.

Usability guru, Jack Nielson, explains in a recent Alertbox Column that most users focus only on what interests them or what they expect will give them the answers that they need while ignoring the other content. Known as “Tunnel Vision,” this phenomenon can make the difference between click-throughs and deleted messages.

Let’s consider an example. You design a newsletter advertising your website’s 20 percent off sale. You include a headline, an image, a block of text that includes a coupon code, and a call to action that says “Shop Now.” Nielson’s usability research suggests that if you haven’t stated the coupon code in the headline or included it as part of the call to action, many subscribers won’t see it. It’s a phenomenon similar to banner blindness, where readers ignore portions of the screen that they think aren’t essential to the overall message. If the coupon code is necessary in order to receive the savings, you’ll need to follow a few design tips in order to keep it within your subscribers’ field of vision.

• Put important elements near each other.
  If your image shows sale items and information, try putting the coupon code within the image or as the image caption. If subscribers must read through a block of text in order to find the coupon code, they may miss it altogether.

• Include essential info in the link.
  People tend to focus on click-able elements within an email design. Your call to action button and any nearby links should contain the essential information you’re trying to communicate. So instead of using a call to action that says “Shop Now,” try “Save 20% with coupon code FALL2012.”

• Test with actual users.
  Designers have difficulty recognizing usability problems with their designs because they already know where the important information is and their eyes gravitate toward it. They might not recognize where tunnel vision might occur for the average subscriber. Creating simple A/B split tests can point out problems that keep your readers from noticing the important stuff amongst everything else.

Tunnel vision means that users often don’t see things that are right in front of them. By grouping important elements together and putting essential information where readers tend to look anyway, you can boost your click-through rates and ultimately, your conversions.