The most common types of problems that hurt the results of a website are:
The message you are trying to send is not the message that is being received. It could be that your messaging is unclear or your content poorly showcases your offerings.
Information that visitors need in order to make a decision could be missing. Or maybe you are using a nonobvious term to describe something in the nav. For example, calling something “Solutions” instead of “Products” There are many ways that content can cause problems in a site.
Structure / Navigation Problems
Your visitors can’t quickly find what they are looking for so they give up. Perhaps this could be because there are too many options in the Nav. Or your underlying information architecture is confusing. Or perhaps you need a search function so that visitors can get directly to where they want to go instead of trying to navigate there.
Some site designs are so bad that they actually turn visitors away. For example, if you are selling a luxury product but your site looks more like Craigslist. Or perhaps you have overdone it with the animations and transitions and so scrolling through a page because unbearable and visitors bounce. Maybe your design is hiding relevant pieces of information or your CTAs don’t stand out enough or look like buttons.
This happens most commonly when your designs have not been properly designed and built for mobile. Content can be the wrong shape or cut off. Pages can require weird scrolling or they can feel endlessly long. CTAs can be hidden from view and Navigations often end up in a hamburger menu. These are one of the most common types of problems and, thankfully, some of the easiest to fix.
Engineering Quality Problems
Engineering Quality can get you in two ways. First, if the site is extremely slow, visitors will leave before they even have a chance to hear about what you’re offering. Second, poor engineering can lead to a site that is excessively buggy in one or more browsers. This can have serious consequences.