In practice, this is Miku's creators and associates trying to find out where her fans live, or at least the nearest major city to which they could travel, in order to work out where best to hold events and sell their products.
This is all part of the 'coming to the west' drive that has already begun with the Project DIVA-F game and the Los Angeles Mikunopolis and other American continent concerts that first happened some two years ago. Now they are looking toward the UK and Europe as well.
I have registered my 'location' as London from the UK cities provided, at this Web page, and I recommend any Miku/Vocaloid fans to do the same, to help build up a comprehensive picture of where we all are and how strong an interest there is here, rather than (say) France.
There is nothing ominous that I can perceive in any of this, as we will by now have realised from Crypton and the other players' track record within this strongly fan-driven market. We just need to show that it is worth their while mounting an official concert here in Britain one day, and marketing their merchandise here as well. There is even a draw for what look to be at least two prizes. Pass the word!