I see a lot of sellers using scans of coins instead of photos. I just don't get it. There is no way to tell anything about the coin with the scans I see. Some coins look like they could be great but if it's only a scan I pass.
There is an enormous lot of information available from scans. They are as good as any camera at illustrating the coin's technical details, and with familiarity one can easily draw conclusions about some aspects of surface preservation - scans depict reflectivity well in inverted fashion (reflectivity shows as black on a scan). Furthermore, scans do not unfairly highlight frost breaks and the like, as digital photography does. My ideal "Guess the Grade" post would include both scans and photographs. No, you won't get any true indication of color and/or hints at cleaning, and that is admittedly a big problem. I think people use scans because they're not capable of making a camera shoot a clear pic of a coin.