bob,
If you select the zoom option and are paying for it, you should receive it. If you have a copy of an old listing and your
ebay billing for that listing, double-check it. If it doesn't zoom, contact
ebay for resolution. I haven't had any problems with mine when they are loaded into the
ebay site and appear on the top left of the auction listing. If they are loaded into a photo-hosting site and appear in the body of the listing, your issue is with the photo host. Most folks don't make their pictures large enough in my opinion ... too many "moon shots". I make mine at least 1200x1200 pixels and crop out everything but the coin.
As far as where to list ... that's a toughie. You'll get a far greater audience on
ebay, but you'll pay for that. Here you deal with nice, honest folk but you may not make a killing on the sale. That's the trade-off. It's up to you. You can also list on
ebay and post the links here in the
ebay sellers section. If you aren't out to make a killing, I'd like to see them listed here first with a set price (items for sale) and if they don't sell, then offer them on the Bay.