Of course that is true Teeth, if the average was positive, the lottery organiser would lose money... money does not appear out of thin air.
But hey, what if...
In my case, I don't need the gold since I rarely even play any more, so may as well throw it away in random events like this. And if I happen to win, well my loom collection will be enlarged.
Also the "originally 10 tickets but more later" will make more people take part, smart way to entice people.