Site’s speed is very important for your on page SEO and the overall performance of your site! There are many factors which can improve your site’s speed – installing special plugins (such as W3 Total Cache), CDN usage, better and faster hosting providers and many more.
Images and reducing their size is an important factor as well! There is one site called http://www.smushit.com/ysmush.it/ where you can upload your pictures and it will smush and decrease their size without loosing the quality! One article about this topic is written here. However, if you have a lot of images on your blog you can save your time and use WP Smush.it plugin to bulk decrease your images’ size! Watch the tutorial below and discover how to do it easily!
WP Smush.it Video Tutorial and Review