Knifecenter has a physical location, and they do sell items from this location, so I guess that qualifies them. Also correct me if I'm wrong, but Amazon is more like a marketplace of sellers with fixed prices. If you look at the description of an item, it usually lists what company or person is selling it.
Uhh, not exactly. Amazon is a company themselves. They ALSO have a marketplace, but if you look up an item on Amazon, the Tenacious for example, it very clearly states "Ships and sold from Amazon". Then, further below that, you have links for "buy new" and "buy used", and if you click them, it takes you to the marketplace where you have the option of ordering from various 3rd party sellers, such as Red's Gear and Knife Country, who list the items at THEIR prices(which may be more or less than the Amazon price, with whatever shipping prices they set, including free on some sellers). Now, there are some items on Amazon that are only available through the marketplace(if you search for one of them, when you click the item link it will say "This item is unavailable" but the "buy new" and "buy used" links are still there, meaning Amazon doesn't currently have the item for sale but the marketplace sellers do), but the VAST majority of stuff on Amazon is available FROM Amazon, not just the marketplace sellers.