The information in this post from DGP4SL Blog is extremely helpful and I really, really wish I’d known some of this before, as I’ve been somewhat (okay, alotwhat) cavalier about my Magic Boxes.

Especially helpful: turns out its a good idea to have duplicates, in case your “main store” sim is offline.

I’d never known how to get the Marketplace to update their list of servers: you have to go a bit “old skool” at the SL Exchange site. So THAT’s why it’s still live…

That’s all well and good but how does the Marketplace know which Magic Boxes you have? The answer to that question is a bit more complicated. Since the Magic Box was originally created for the old XStreet SL (and before that it was called “SL Exchange”) web site, you actually have to use the old XStreet SL site in order to “teach” the Marketplace about all of your Magic Boxes.

Link: Care and Feeding of the SL Marketplace Magic Box : DGP4SL Blog