It also works very well with animated GIF files. It is free for non-commercial users and fairly inexpensive for commercial users. There are other software packages out there that can accomplish the same the, but I haven't yet used any that are as effective. You can use animated GIF images. However, keep in mind that animating an image will make it larger and make it take longer to download.
Animation can also be very distracting.
The biggest problem with animation is that browsers don't deal with it as efficiently as they should. Therefore, if your visitor has a low-end system with a small amount of RAM, their whole system will slow down the entire time the animation is playing. You also need to decide how many images to place on one page. Most browsers need to open a new connection to your web server for every image on your page. That can really slow things down if you have lots of images.