It does not seem to cause any problem to Amazon, Apple, or the vast majority of other shops out there. The biggest shop debit your card when they ship and let you cancel at any time.
Google is crafting buzz like Apple is doing with the queues at the Apple store or their irritating "reserve your iPhone" that in reality does not reserve anything. A difference though, if you don't want to bother, you can simply order online and it get it delivered the old boring way once it is back in stock. The Nexus can only be bought online.
(disclaimer: a bit bitter after having tried to buy a Nexus 4 today)
On the other hand, why not just wait a week 'till all the fervor is over. If you're cool-headed enough to realize this is all to build buzz, then surely you can wait a week.
Google is crafting buzz like Apple is doing with the queues at the Apple store or their irritating "reserve your iPhone" that in reality does not reserve anything. A difference though, if you don't want to bother, you can simply order online and it get it delivered the old boring way once it is back in stock. The Nexus can only be bought online.
(disclaimer: a bit bitter after having tried to buy a Nexus 4 today)