The license is good for 1 computer, per the EULA. Hence the reason that I purchased 3 separate copies...I'm using it on 3 different computers. So, $15 invested in total on my part. So, I have 3 total serial #'s.
It was funny reading the post that was linked above. I build a ton of VM's too, but I guess I don't find things like Start8 absolutely critical to the point where I have to run it on each and every VM. As long as it's on my main laptop/desktop....I'm fine. I can work around a start menu on other testing computers.