In Harrahs (CET) system status levels: Platinum, Diamond, Seven Stars (everyone who signs up is initially Gold) can only be obtained through gambling.
Rewards points (which can be earned from other sources) can be used to cover lots of things (food, room, etc.) aren't that good a deal, since 1 point correlates to spending $1.00, and each point "buys" you $0.01 worth of amenities--so if you got, say, 2500 points (from non-gambling sources), it would give you $25 of "buying" power.
[Even "small time" gamblers, in Harrahs system, will get offers for free rooms (at off periods)...]