Similar to the previous Kerastase vouchers (http://www.ozbargain.com.au/node/46781)
Obviously you need to purchase a hair service. I think its a pretty good bonus, considering some salons like HairMachine charge $33 just for a treatment. I had no problems using mine last time.
T&C
Vouchers will be emailed to email address submitted on the claim form. Contact a participating salon to make an appointment to redeem voucher before 30th June 2012 (subject to appointment availability). Purchase any in-salon hair service and surrender printed copy or show electronic copy (via their smartphone) of voucher at start of appointment to receive complimentary treatment valued at $35 (inc GST), subject to availability in salon. Voucher not redeemable for cash or credit. Limit 1 voucher per customer. Vouchers obtained by or through fraud or other illegal activity are invalid. Claimants using multiple aliases may be disqualified. Voucher cannot be used in conjunction with any other offer. Customers must adhere to any additional conditions imposed by a participating salon. Kérastase is not responsible for the service provided by participating salons.
Locate Kerastase Salon here : http://www.kerastase.com.au/salon-institut-kerastase.aspx
Best to call and confirm they are participating.