Recently received my new rewards from Nuffnang, and from a forum, Discuss SG.
Basically, you post, contribute and participate to gain credits and for every 1000 credits, you get to cashout $20. For 2500 credits, $50. There are other vouchers to redeem too.
You can join the forum here:
Glad to have extra pocket money to relieve some debts load, hope will be able to cashout again soon!