I was doing some google searches on this subject and couldn't find anything definitive. I was just wondering what the actual number of units sold was for the Expansion Pack, including pre-orders.
I don't know whether or not its common practice that companies release such information, but usually you have a general idea if the expansion sold well. In this case I don't really know.
I'm just curious if this will be the only Expansion Pack we see. If MotU sold well, I would assume there would be another expansion pack in the works. If not, then maybe that's the only one we'll ever get.