The currency expires by your membership year. e-Rewards also gives members an extra 30-day grace period to redeem expiring currencies. Log into your account and look for "Membership Year Ends." If it ends on 3/31/09, you'll have to redeem them by 4/30/09.

If you are confident you'll earn another $25 credit by the end of your membership year, then wait for it. If not, just grab 3K HH points now. However, if it took you 10 months to "earn" $50 credit since last May, chances are you won't get enough for the next level of HH redemption before your year's up.

BTW, if you happen to be a panel member, e-Rewards will send you a notice by the end of your membership year and extend your currencies for another membership year (if they decide to keep you as a panel member for another year).