I have to experiment with this a bit more, but I see that other photographers have the same idea -- a desirable feature is global removal of file extensions in the Item ID. Fortunately, I found this wish-list thread before posting a new thread/title for the same thing.
I have read most, not all, of the related postings. I understand that Shozam defaults the Item ID to FileName.ext, where "ext" is usually "jpg" because, for example, Shozam doesn't import Photoshop (.psd) files. But the only importable files are .jpg, .bmp, .png, and .gif. I see little reason to have two identical file names with different extensions if those are the only possible extensions. The unique ID is really a combination of Item ID, plus Item Name -- or potentially those two plus Item Price.
I think that casual buyers won't know much about file extensions with respect to print quality, but the implication that one is selling JPG prints is something I insist on avoiding. Even if one had the ability to import into shozam both a TIF and a PSD with the same file name, that is not a very useful distinction from a sales viewpoint. More useful would be distinctions such as quality of print from the same image; e.g., ordinary inkjet, Epson pigment prints, types of paper (glossy, canvas, watercolor, etc.).
The least useful identifier, in my opinion, is the .jpg that I've created solely for the purpose of importing images into Shozam. I understand the programming reasons that make it "easier" to vertically stack button and Item Name. But that is a severe limitation because it makes the addition of more than about two or three buttions nearly impossible. Allowing for multiple varieties of printing for the same basic image -- size, quality, paper, etc. -- is an essential requirement for a sales item (photographs) that are printed to order. I'm not going to stock up on 13x19 pigment prints for a few hundred images, but will gladly print one for the customer who wants to buy.
I strongly urge the addition of an option to globally remove file extensions from the Image ID -- with a Restore option to restore accidental removals and some means of allowing more sales combinations. :)