Agreed. The file they send you is too small to be useful for much of anything.
502x70 resolution / 73.9KB file size.
I paid for this service one time and the image below is exactly what I received. They only sent an image of the front cover, not the back. IIRC, they charged me $5 for this image and I had to call the CGC to remind them to send it to me.
It's a pretty image, it just isn't large enough to be useful.
You can call or email them requesting a larger size file for them to send you. I had them send me 2 different size files.