Now that I’ve got your attention. Let’s be clear, I’m talking about the size of images when making them web ready! Website speed is something that is often overlooked but believe it or not, if images or pages take longer than 2-3 seconds to load then people click off and will go elsewhere.
In a time-starved world you need to make sure your images are size-optimised for web use. As a rule of thumb images should be around 100KB, scrolling homepage banners might be larger to maintain the quality but keep an eye on this because it could be a matter of a conversion or not.