“A high percentage of effects in any large system are caused by a low percentage of variables” 80/20 Rule – also known as Pareto’s Principle, and Vital Few and Trivial Many Rule.
The 80/20 rule can be observed in most parts of life. If (like me) you google it you’ll see just how many topics there are on the subject. From articles about time management, traffic on the roads to company revenue. But, applied to eCommerce it means that approximately 80 percent of the site’s usage will involve 20% of it’s features.
Why is the 80/20 rule important?
Understanding this allows UX designers to simplify user interface by identifying the critical ~20% of features and making them readily available to the user. This simplification can allow designers to tuck away other functions from a design, allowing users to more efficiently find and complete a desired task on the website. When time and resources are limited, we must resist the urge to drain resources on the non critical 80%.  Scarcity of skilled designers and developers is at an all time high, so it is therefore critical to focus resources to see greater efficiencies in the design and development process. Designing and testing can be focused on what is important by reducing time spent on what is not.
Data Driven Decisions and User testing
In order to get this right you will need to cut out 80% of the fat. In order to identify the right 80% you will need to go through data and/or perform user testing (depending on whether or not you have access to real data). If you have not made user testing part of your process, then you must be prepared to have a bigger drain on your user experience and development teams who have to design and build more features that could end up as more distractions for the user. Understand what’s important, don’t get distracted with what’s not, focus your teams efforts to create a better user experience.
