Like, do you use the memory palace at first, and later it just fixes into unconsciousness? Because there is no way greeks really had hundreds of memory palaces where they structured all their knowledge, right?
As for scale, many memory workers use a linked list as well as the memory-palace array. Associate each item with the previous item, and you don't need 10,000 room palaces; just someplace to put the head of the list. That's how I memorize decks of cards: http://blog.diiq.org/post/3366119815/what-are-the-step-by-st...
An excellent resource is Lorrayne and Lucas' The Memory Book:http://www.amazon.com/gp/aw/d/0345410025/ref=redir_mdp_mobil... , which has been lifechanging for me.
As a matter of fact, an informal list of places I can use as memory palace, as I know them from memory ranges around 70 "palaces" with between 4 and 15 rooms each. If you cram 3 items per room its around 700 things to remember. But you can get better.
You can also use association (I am about to write a post about it) to get facts about books, people, things without using a new palace for each kind of data type.
> I don't know if its web scale.
I also noticed a problem I have with using something like the Dominic System to store phone numbers, which is remembering the first image.. after that, this image just "pulls" the others by association.