Found 7th Jun 2016
Empire Cinema currently have a voucher you can print off to get yourself a free small drink. I've made a pic with 4 vouchers on that ill add in first post that you can print off. Alternatively just login to your account and print off. Voucher is a PDF so you can print it multiple time. Doesn't seem to mention about buying a ticket to get the free drink but i guess it kinda implies.