Today at Subway I noticed a sign saying "Free Cookie" for a Survey.
All you need is to visit the link - http://www.tellsubway.co.uk/ContentManager/Controller.aspx?page=Home/Home
Use the receipt from the store to get the identify number for the individual store, I used the following link to simply find my local store ID - http://www.subway.com/storelocator/
All you need to do is complete the survey about the quality of service and food, literally took about 30 seconds. You get an email with a QR code, you can print it off or take a picture with a decent camera phone (as I did), take it to the Subway and scan it.
Its say you need the receipt and the QR but I never get a receipt and the employee was happy just to scan, confirm and give me cookie!!
Offer ends - 09/03/2013