If you cancel your membership, your GameFly Rewards Level will be reset to 0 and you will lose any percent-off discounts you may have earned up to that point. If you have received GameFly Dollars, you will retain them until they expire.
When you decide to reactivate your membership, you'll restart at level 0 and begin accruing GameFly Rewards once again.
To learn more, see GameFly Rewards.