Ketchup or Mustard hotdog, PS the bandwith is the image hosts...

Ketchup or Mustard hotdog, PS the bandwith is the image hosts problem as they are hotlinked..

However

Buy say 100 meg of web space to host images and charts
the size and image format can be controlled and deleted say 3mthly..

You just need a Host website .Cheap as chips for an advertiser..who can tag a small add on each image..

checkout
xs.to Hosting
Pictiger.com
PicFury.com

One of your guys could write the software, Its very simple..