Sort of true but not exactly. Obviously they are designed to make money, thats a no brainer, but they by law have to pay out a certain percentage of money taken. This can usually be adjusted by the machine owner, but can only be adjusted within a built in range, a owner couldnt make it 1% payout for example, as that would be against gambling laws, sort of why there is such a big discussion about thigs like FIFA packs that offer random odds of less than 1% and are purchased with real money.