I myself was asking the same question!
I know that this software only lets you make 1 copy to a harddrive, but you buy another computer and all you have to do is copy the harddrive..or if you can't manage that, ...copy the originals again! and run another show, and so on and so on.
I know a guy out of Phoenix, Az. who is doing exactly that!!
He is a programmer for Cox Cable. He has written his own software to run his karaoke shows from his laptops...like MTU has done.
He has copied his disks and has duplicated his system, to run multiple shows and then some. He has done this with the idea that HE built his system and designed it, so why can't he do it. He put all the work into it and he is not selling his idea, but he does profit from it, because of his karaoke shows. He now has shows is 5 States, From Arizona to Alabama.
ADMIN NOTE: He has the right to distribute HIS OWN WRITTEN program however he wishes. However, if he is also copying CDG songs he has imported, this is INCREDIBLY ILLEGAL!!! 
This is a quandry,... I myself would have no problem buying more than 1 laptop, and I have the money to do it, But does it become a moral problem when you copy the Originals to more than 1 laptop...or if you copy your Original Harddrive, or is this a legal question?
Rickokie