Don't get me wrong, I love images. But I think there are limits. It has no compression once the images is saved in the format. What is transferred is what is displayed. Thus it is good for pictures with little detail or lines.
Faces show up poorly.
Gifs can also be saved at 256, all the way down to 2 colors and still look crisp. JPEG JPEG is a compressed format. That means it is sort of squashed together when it's put away. JPEG is best for photographs, or equal images. I know they look great, but waiting for them to load is dull.