PayPal: 50% Cashback upto Rs. 400 on Rs. 50+: on 1st 2 transaction between 26th oct 8PM to 7th Oct 2010 Source
HDFC Cards: 10% discount upto Rs. 750 on Rs. 5000+ till 19th Sep source
Airtel Payments Bank: Rs. 200 Cashback on Purchase of Rs. 2000+: Cashback would be credited within 72 business hours in user’s Airtel Payment Bank wallet or Savings Account. (Terms & Conditions)