Sometimes we engineers are so focused on functionality that we don’t bother with usability. Let me see if I can explain:
we put the focus on defining the use case, we concentrate on giving users what they ask for, but not what they need.

But do we ever observe how users actually use our system? I have several stories about how we came to realize that our users were doing manual work to fit their input to our systems, work that wouldn’t have been necessary if they had described to us how the information really arrived, instead of asking for an ideal format of how it was supposedly meant to arrive.

That’s why I’m set on getting the developer/programmer closer to interacting directly with the user. [What’s more, I’ve always thought it’s a good idea for programmers to use the systems they build under the same conditions the user has. That’s how you discover bugs, or incomplete or inadequate features.

I’m going to tell you a story, one that’s famous among the people who work in usability engineering (yes, there’s an engineering discipline for that and it’s very important).

It’s the story of the three hundred million dollar button.

The article was published by Jared Spool in 2009, and you can read it at this link: https://articles.uie.com/three_hund_million_button.

What follows is a translation of sorts of the original article (Spool includes a link to a Spanish translation in his post, but frankly I found it very bad; fair warning, though, this is neither a literal nor a complete translation):

How changing a button increased a site’s annual revenues by $300 million

It’s hard to imagine a form that could be simpler: two fields, two buttons, and one link. Yet it turns out this form was preventing customers from purchasing products from a major e-commerce site, to the tune of US$ 300,000,000 a year. What was even worse: the designers of the site had no clue this was a problem.

The form in question had the fields Email Address and Password. The buttons were Login and Register. The link was Forgot Password. It was the login form for the site. A form users encounter all the time. How could they have problems with it?

The problem wasn’t so much the form’s layout as the way it behaved. Users would run into it after they had filled their shopping cart with the products they wanted to purchase, at the moment they pressed the Checkout button. This login form came up before they could enter their payment information.

The team figured this form enabled repeat customers to purchase faster. First-time customers wouldn’t mind registering because, after all, they would come back for more and appreciate the expediency in subsequent purchases. Everybody wins, right?

“I’m not here to be in a relationship”

Usability tests were conducted with people who needed to buy products from the site. They were asked to bring their shopping lists and were even given the money to make the purchases. All they had to do was complete the purchase.

The first thing discovered was how wrong the team was about first-time shoppers. They did mind registering. They resented having to register when they encountered the page. In the words of one shopper: “I’m not here to enter into a relationship. I just want to buy something.”

Some first-time shoppers couldn’t remember if it was their first time, and became frustrated as each common email and password combination failed. The observers were surprised by how much they resisted registering.

Without knowing what was involved in registration, all the users who clicked the button did so with a sense of despair. Many vocalized that the only thing the site’s owners wanted was to get their information to pester them later with marketing messages they didn’t want. Some imagined nefarious purposes and an obvious attempt to invade their privacy. (In reality, the site asked nothing during registration that it didn’t need to complete the purchase: name, shipping address, billing address, and payment information.)

Not so good for repeat customers either

Repeat customers weren’t happy either. Except for a few who remembered their login information, many got stuck on the form. They couldn’t remember the email address or password they had used. Remembering which email they had registered with was problematic: many had multiple email addresses or had changed them over the years.

When a customer couldn’t remember the email and password, they’d try guessing them multiple times. These guesses rarely succeeded. Some would eventually click the link to recover the password, which becomes another problem if you can’t remember which email address you originally registered with.

[After this study, an analysis of the retailer’s database was carried out, only to discover that 45% of all customers had multiple registrations in the system, some as many as 10. They also analyzed how many people requested password recovery, and found it reached more than 160,000 per day. 75% of these people never tried to complete the purchase.]{style=“letter-spacing: 0.01rem;”}

The form, intended to make shopping easier, turned out to help only a small percentage of the customers who encountered it. (Even many of those customers didn’t get much help, since it took them extra effort to update incorrect information, like changed addresses or credit cards.) Contrary to expectations, the form was preventing sales, a great many sales.

The US$300,000,000 fix

The designers fixed the problem simply. They took away the Register button. In its place they put a Continue button, with a simple message: “You do not need to create an account to make purchases on our site. Simply click Continue to proceed to checkout. To make your future purchases even faster, you can create an account during checkout.”

The results: the number of customers purchasing went up by 45%. The extra purchases resulted in 15 million dollars the first month. In that first year the site took in an additional US$300,000,000.

The author says that on his answering machine he still keeps the message he received from the CEO of this retailer. It’s a very simple message: “Spool! You're the man!” It didn’t need to be a more complex message. After all, they had only changed a button.