More so than a static plot, an animation is innately interactive. It is much closer to how we take in the physical world, and therefore our minds can often assimilate its message in more meaningful ways. Another advantage of an animation is that it provides a convenient third dimension in which to display your data. So, rather than trying to cram all of your information into a single static plot you can spread out your data along this orthogonal axis, thereby reducing clutter. To put it another way, if a picture is worth a thousand words, then how many words must a whole movie of pictures be worth?