Product returns in the U.S. cost a hundred billion dollars a year, and a recent study by Elke den Ouden, of Philips Electronics, found that at least half of returned products have nothing wrong with them. Consumers just couldn’t figure out how to use them.

That’s one of several interesting observations James Surowiecki makes in a recent Financial Page column in the New Yorker. Surowiecki’s piece focuses on the obstacles to creating usable consumer products, but you don’t have to leap too far to make a comparison or two to website usability.

The Philips Electronics study cited above got me wondering about the revenue e-commerce site owners leave on the table when they offer visitors a sub par user experience. While it would be somewhere between disingenuous and stupid to count every site abandon as an order sacrificed to poor usability, it’s worth considering what fraction of these missed opportunities better usability could in fact reclaim. And then think about that portion’s worth in terms of revenue, customer satisfaction and lifetime value.

Also interesting, especially in light of Surowiecki’s authorship of The Wisdom of Crowds is his explanation of why consumer electronics products continue to suffer from “feature creep” despite designers and engineers increasingly knowing better. Dependent on their position in the purchase cycle, the crowd may not actually be so wise.

It turns out that when we look at a new product in a store we tend to think that the more features there are, the better. It’s only once we get the product home and try to use it that we realize the virtues of simplicity. A recent study by a trio of marketing academics—Debora Viana Thompson, Rebecca W. Hamilton, and Roland T. Rust—found that when consumers were given a choice of three models, of varying complexity, of a digital device, more than sixty per cent chose the one with the most features. Then, when the subjects were given the chance to customize their product, choosing from twenty-five features, they behaved like kids in a candy store. (Twenty features was the average.) But, when they were asked to use the digital device, so-called “feature fatigue” set in. They became frustrated with the plethora of options they had created, and ended up happier with a simpler product.

Fascinating stuff in and of itself, and it seems like there’s at least one instructive parallel to the site design process. Just because users say they want a feature (think focus group) does not mean they’ll be ready, willing, or able to use and enjoy this feature if you go ahead and add it your site.

Whether you’re designing a cell phone, a software application or a new payment method for your Checkout, the challenge is that each additional feature demands that your user make an additional decision. That decision can be as seemingly benign as “Can I afford to ignore this button?” or as expletive inducing as “What the &*%#! is this third scroll bar for?” But what can you do, ignore your customers’ requests? There’s no perfect answer. But your implementation can make a difference and user testing early and often significantly increases your chances for success.