Some analysis:
The site is built with wordpress with some kind of shopping addon theme, and the entire site's URL structures follows the so called RESTful API structure. basically means that the urls are "pretty" and so can be "guessed", so you can access pages directly through url if you guessed it correctly(this is not "safe" but makes developing for mobile and web browser at the same time easier because both platforms can essentially just make the same API requests.), for example if you want to access their shop just do baseurl/shop, the url structure behaves very good and it is very easy to guess what pages should have what url.
I think the fake clack maker is not very good with computer so they chose some wordpress shopping theme that could not handle time sensitive sales. For example just by guessing the URL, some users were able to access some restricted pages that should not have been turned on to begin with.
I did some digging through the URL structure, even before the sale, it was apparent that some users realized that they could access pages that's not supposed to be turned on:
http://www.reddit.com/r/MechanicalKeyboards/comments/2ev30u/upcoming_keycap_sale/ck3y5i3But the most interesting part of the website is the "news" sectioned. It is completely native wordpress. You can even register with the wordpress blog backend. Meaning that the fake clack makers either are amateurs or rushed their website job, that they forgot to turn off wordpress's native registration... If you've used wordpress extensively before, you know this means that you might be able to see the backend of the website... So I registered an account and what do I see? Their complete shop statistics on how many purchases there were.
SO, if you are wondering how much this did sell? Go to their news section and register an account with them.
For science. I'm not going to list the exact numbers, go see for yourself. But the number of orders and the total sales(dollar amount I assume) checks out to be about 2 fake clacks per order on average.