A google report outlines the key role of website performance related to opening speed to deliver a frictionless experience.
consumers will leave a page that takes longer than three seconds to load
Since people are using the Smartphone as never before during their micro-moments, they need to access to digital content through mobile very quickly, while almost 80% of consumers would leave the website and not close the transaction in the website due to its low performance.
How to increase the mobile speed performance of your website?
In general, you can apply the concept of less is more. Start by selecting and reducing the page elments that will be displayed and keep following this line for each aspects like images and so on.
Follow this guide
An and Meenan (2016) Why marketer should care about mobile page speed. Available at: https://www.thinkwithgoogle.com/marketing-resources/experience-design/mobile-page-speed-load-time (Accessed: 15 June 2017).