Users, visitors, clients, customers. Whatever term we may call them, these are the people we built the website for – your target audience. Speed is a crucial factor in creating a great first impression and user experience for your customers.
Google has indicated that site speed is a factor in their search engine algorithm to rank pages. This means faster website pages will help your site rank higher on their search engine results page. PageSpeed Insights is a tool developed by Google that is used to analyse website performance.
A slow website will result in losing traffic as users click the back button and visit your competition instead. A faster website will result in an increase in conversions/sales.
For further information read Why Performance Matters on Googles Web Fundamentals website which goes into more detail and provides case studies.