That email address and phone number is for Walt Disney World's Merchandise Mail Order staff. They handle remote sales of all WDW merchandise. (Yes, you can buy just about anything they sell at the theme parks from home.)
The system works best if you know beforehand what you are looking for and where it can be found at the parks. For instance, if you describe a shirt at MGM's Keystone Clothiers, they will first try to find it in their database. Failing that, they can call over to the store itself and try to get a SKU from a Cast Member based upon the description.
If you're trying to buy something blind ("I want a BoardWalk t-shirt"), the process is going to be a bit more challenging. There are no catalogs and the MMO folks can't email you pictures of the item or anything like that.
I think it would be nice to have some sort of catalog, but still of somewhat limited value. I tend to think that most of the sales would come from those who are very new to
DVC. Speaking from experience, once you've been Home 2 or 3 times, you've had ample opportunity to stock up on DVC stuff. And the desire to shop isn't going to subside once the trip begins--Disney will get your money either way.
I'm sure they do lose some sales due to lack of mail order, but I guess someone at DVC believes that the revenues wouldn't offset the cost involved with providing such a service.
