Harrahs and MGM systems, base their "point" systems on how much you cycle through the slot machine, winnings and losings don't (so far) count. With the MGM "MLIFE" system, I can't (I have not received the official initial mailing) tell how things will be computed.
[When I last played at Gold Coast, about 8 years ago, they based their system on how much you WON.]