Animation is one of the best ways you can draw attention to a particular part of your web page where an important message lies. For example, there are several sites today which uses an animated banner saying “HOT!” to draw their readers away from the text towards whatever you want them to see, for example, the latest discounted products or the newest book released. Others also use a glistening log for “email us” or “specials”.
One thing you need to keep in mind when using animation is that there will always be an overhead or delay in loading the page. For example, with an animated gif image (an image constructed using multiple still frames and saved as a single file), instead of a seamless movement, the frames can become apparent when viewed in a slower connection.
Like audio, animation needs to be used appropriately. Use it to enhance the website in a meaningful way. Some designers recommend animations only for websites which cater to a corporate target audience since most of these people do not have the time to go through each of the pages of the site to find the information that they need. One rule of thumb when it comes to animation is this: “if in doubt, cut it out”.