A fairly old article but still very relevant today “Does it seem like the pages on your website take forever to load? If so, it’s essential that you find out where the bottleneck is and take steps to remove it. Why? Because Google is now factoring page load speeds into their ranking algorithm as part of their newly minted objective of sending searchers to the most user-friendly pages possible. There are a number of factors that can cause a web page to load slowly. One common culprit is the use  of large image files, each of which can add precious seconds to overall page load time even if the user has a fast Internet connection. And if you run a blog, using too many widgets and plugins can put your site into the slow lane.” via Is Your Web Host Sabotaging Your Google Rankings? – Exploit Online Demand.