Download the tcc Rewards+ app and sign up as a member to get a free welcome drink e-voucher (worth $9.50). If you're an existing member then you will get a 50% discount e-voucher.
Lasts for a month from the time you complete registration. T&Cs "appear" to be strict (i.e. it suggests you can't change to something else) but who knows how strictly they'll enforce it.