Page speed is a ranking factor in Google but it is also a major factor when it comes to conversion optimization. People do not like to hang around whilst your website is taking its time to load. If your site takes longer than 4 seconds to load you lose the some of the potential clients/ customers that visit your site. If the coding in your site doesn’t load you will not see the session in your analytics. Having good page speed also means search engines like Google can read your site more efficiently. This will improve rankings as this is something Google are focusing on more and more.