it would depend on the lottery, but I would also guess that Rob is right

on the other hand you should have told us earlier so we could get a ticket as well :-)

My take on lottery tickets is
1) buying one lotter ticket increases your odds of winning much more then not buying :-)
2) Even if I loose the money I spend goes into the system (like my friend says, a tax on stuppidity) but a tax is better then ligning the pockets of some rich guy (like a private casino)