JPEG is not a compressed GIF! JPEG is an excellent format to compress true
color natural images. JPEG images may or may not be smaller than GIF images
depending on how high the compression parameters are set but JPEG will generally
be smaller for most images. The lossy compression technique used by JPEG may
blur important details of an image such as fine text. JPEG may take
longer to display than a GIF image depending on the speed and color resolution
of the client. Information providers have to make plenty of decisions on
how to present their information, JPEG vs GIF is just one more.
Leo Lucas