I am getting slightly confused at the attempts to prove something with meaningless stats...
None of the European pre-releases were advertised on the Pokemon-TCG website, we had 2 weeks in the UK to find a venue advertise and run the event, and we had a great turn out given all that.
But how the advertising that was done across various Pokemon Boards and on the Pokemon TCG site would have affected the UK is unquantifiable and therefore you cannot compare the UK, the European or any other pre-releases against each other on any kind of Statistical analysis without taking so many factors into account that the Stats become worthless.
Adding in factors like Demographics, Financial Modifiers, Social Economic Groupings, Location of Venue compared to transportation links, and so it can go on.
We had fun, the event paid for itself, everyone went away happy.... result.
Now can we forget the meaningless stats please!