That's because the addresses are different for each game, they don't remain the same. It's called DMA. So it won't work If everyone tries to use the same address.
He is correct.
I did it with ArtMoney, searching for 4 byte integer addresses. I got seven in total, and you need to change all of them for the hack to work.
Edit: My bad. It doesn't work. The number goes up, but the game crashes if you try to make use of the new minions.
[Edited by Abelius, 9/14/2011 6:37:08 PM]