Scientists have long studied the psychology of persuasion, such as gestures, words and behaviors can make, alter, predict or influence our perception of reality. But what are the principles and techniques that are the basis of these studies?
When you start to project a web page, you must consider a lot of variables and parameters. My personal target is to create pages very light to get a fast download on our browser.
One of watchfulness I get to do this is to reduce server calls. Less calls means less net traffic. Less net traffic means less server work. Less server work means less server operating system work. Less of all means less client waiting time to render the page.
About images, I prefer to use Css Sprites everytime is possible. Next picture shows you differences between simple images and sprites images.