Etihad Airways Guest program members are eligible for complimentary ticket to Expo Milano 2015 and to have access to a Premium Etihad Lounge with good (and booze hopefully).
The email that Etihad sent contains a coupon code for redemptions + another one for 25% off Expo tickets.
You can access Etihad’s website for this promotion here.
Here’s copy of the email that Etihad sent out:
This email from Etihad Guest came about the right time. I am on my way Italy early next week and was going to pay a visit to Milan to check out the Marriott’s Moxy brand. This would be a good time to visit the Expo as well.