Godfrey
somewhat colored
consider the possibility that they have a high res device, say 2-5x higher than most flickr viewing devices were a few years ago, and they'd like to see your image larger than a thumbnail.
Then they can buy a print at whatever size I offer. Sorry, that's not my concern at all. Photo buyers, that is, people who actually BUY from images on the web, know that an online image is low resolution and only a representation of the full size image.
G