When buying something online, how much do you care about how the buttons are laid out? More than you might think.

With content changes on our websites, we typically use what’s called “A/B testing” to see how
those changes perform. Some site visitors (“group A”) see one version of a page; the rest (“group B”) see a slightly different version. By watching the analytics for the two groups, we can see which design “wins” — that is, which presentation is clearer, more understandable, more compelling, and so on.

One day last year, we were experimenting with small improvements to the shopping cart on our Palo Alto Software store. On the page that collects the buyer’s address information, we tried moving the Continue button from the right side of the screen to the left. We made the change and started the test—and
conversions from the address page immediately dropped 40 percent.

Forty percent! Really? All we did was change the alignment on a button. The product they were buying was the same. Nothing changed in the value proposition of our software. The button was still visible and similarly
easy to find. No warning bells should have gone off. But for a huge chunk of our audience, the left alignment of that button was a dealbreaker.

This sort of consumer behavior is surprisingly commonplace. Ecommerce sites like MarketingSherpa are replete with examples, like this case study where an office supply retailer changed the size and color of their buy buttons and lifted conversions by 44 percent.

Making sense of seemingly irrational behavior is the focus of the emerging field of behavioral economics. It’s been in the news quite a bit this week with coverage of “Predictably Irrational: The Hidden Forces That Shape Our Decisions,” a book by MIT professor Dan Ariely that identifies specific types of irrational decisions that people tend to make, and why. For an overview, see the book’s website, or check out Elizabeth Kolbert’s excellent review of the book in The New Yorker.

AvatarJosh Cochrane

Josh Cochrane is Vice President of Product Development at Palo Alto Software, where he manages development of the business planning tool LivePlan.