Rebtel, the exciting international telecom operator, asked me to make a full scale usage test using eye tracking on their public web site, sign up, and their customer self service area. The eye tracking test immediately brought some totally unexpected errors in the service to Rebtel’s attention as well as provided a solid ground for the strategic design and development decisions in the future.

Rebtel is fully dependent on their web site. Rebtel gives people local phone numbers in the country where they live that connect them directly with their friends, family or work colleagues who lives in other countries. The user has to use the site for signning up, handle payment and manage their contacts in order to be able to easily make a call in the future. Any problem in the usability would affect the business severly and usability is therefore of the utmost importance to Rebtel.

7 users was invited to test the site. Each user was presented with a scenario where a close friend was moving to New York and they needed a good way to continue talking without spending a fortune. The users were asked to check out Rebtel’s site, sign up and finally make their first payment using a credit card.

The start page content got good eye sight coverage by the users. However, the start page did not manage to convey the basic features in the service which caused the users problems later on in the process.

By processing and presenting the eye tracking data in various format like for example heat map visualizations of how the users were focusing gives a general idea of what the users were thinking when they are using the site.

Rebtel’s service works a lot smarter than the normal calling card companies around. To take full advantage of the Rebtel service you need to enter the phone number of the person you would like to call in advance on the Rebtel site. The system then creates a local number which is sent with by text message to your phone. If you call that local number, Rebtel will be able to connect you through to the international number to you previously entered on the site, at a very low rate. The cost for the user is only a local call and a fair rate.

The study clearly showed that the site not managed to explain to the users how the service works before they signed up. Even if the start page managed to convey to the users that they could use the service to call incredibly cheap, the users did not manage to understand the basic functionality. The study also showed clearly that the users that tried to sign up without realizing the functionality tended to run into problems later on.

The sign up page heat map visualization shows a easy sign up form working well for the users. However, the form was surrounded with content on the left hand side that distracted the users and in some cases even made the respondents to leave the page.

The users that did not understand tended to begin the sign up process in the hopes that it eventually would become clear, had a hard time figuring out what to do when the sign up was complete. The test clearly showed that without a raised awarness of the Basic Rebtel offer, the likelyhood of actually becomming a paying customer decreased.

After making their first free test call the users were asked to try to add money to their account. This is were the test got really interesting. As it turned out the payment flow contained a few very severe usability issues that caused some of the users to get completely stuck.

Two out of seven users in the test were, by the layout of the billing adress form in the payment process, led to believe that they should enter their credit card number into the field for VAT information.

The way the billing adress form was laid out caused two of the seven users in the test try to enter their credit card details in the field for VAT information. The functionality suggested by the interface was so powerful, that the users did not even notice the headline of the field. One of the users tried for 7 minutes to enter a credit card number without any luck. The lengthy error messages went unnoticed by the increasingly frustrated user.

This result came as an absolute surprise to the Rebtel representative, a web developer who witnessed the test as it progressed. He later said:

“I have worked with reducing the downloading time with fractions of a second for two weeks now, and then I see a user struggle for more than seven minutes in order to enter a credit card number, and finally give up. This shows that nothing is more important than usability.”

The good thing with this sudden awareness was, that it was very easy for Rebtel to attend to the problem. Actually, a hotfix was issued the same day as the test session took place that solved the problem, by simply removing the field  from the interface.

A gaze plot visualization showing how the users responded to different payment providers interface. The more simple solution to the left clearly takes less effort for the users to complete.

The results from the study showed the weaknesses in the site, sign up and payment flow. The results also provided invaluable information  on how the new version of the interface should be designed. I later got invited to help Rebtel to completely redesign the sign up flow as well as the start page and payment flow. These improvements ended up reducing the amount of customer care issues and increased the conversion rate dramatically.

The test was highly appreciated by Rebtel. Maja Lindström, Product manager at Rebtel, expressed the insights gained from the study like this:

Mårtens eye tracking study made us know our users a thousand times better and we at Rebtel recommend all site owners to let Mårten do this kind of study. It is worth every penny. An advice though. When the test is being conducted, make sure you don’t just let Mårten do the test session by himself, make sure you’re there in the room. That experience is like nothing else and beats any written report or live recording you can get.

There is no better way to learn things about how your users think without conducting usage tests. And there is no more effective way in this respect, than Eye tracking. To frequently test and evaluate any business critical application in order to be able to attend to problems and usability issues, is a very effective way of helping you run a successful interactive product.

/ Mårten


  1. 15 August 6:31 Imran Sadiq say's

    Hi Mårten

    As we are offering cheap international calls as Rebtel, I would like to hear an offer about a test on our webpage.

    We are in the process of launching a new website with login pages.



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