Oh god. Why open the webshop at 21:00? It's like asking for the webshop to be DDoS'd by the customers. Opening should have been at 6 o'clock in the morning or something to make it smooth.
The way it is now is bound to cause problems.
We aren't talking about the whole world ordering new iStuff

I guess he will have maybe 300-500 customers and that is not hard to handle on the webserver. And BTW the URL is not known, so people won't go there at the exactly same second, but in the order as they receive the email with URL...
OH LOOK ITS 15 PAST 21:00 AND THE WEBSITE IS STILL NOT WORKING BECAUSE OF DDOS BY CUSTOMERS; WHO COULD HAVE GUESSED THAT OMG