I bought a small drink at BK this morning and noticed there was a sticker on my cup about receiving $5 for taking a survey. Just purchase a drink (small, large, medium, king), excludes beverages in Kid's Meals or Big Kid's Meals and you should have a sticker on your cup about the survey. Each sticker comes with a unique code to start the survey. YMMV.

Finished the survey in about 5 minutes (even though the automated message says about 15 minutes). You don't need to call from your home phone, called from a cell phone and it worked fine. You just need the address to receive the $5. Payment will be mailed as a check (confirmed by hvnsangel -thanks!). I attached a picture of it, sorry for the bad quality I don't have my camera with me.

Tip: to end the survey fast choose the option you only purchased a fountain drink.

Tell us about your Fountain Beverage and WE WILL GIVE YOU $5.00

Fine print:
The limited offer only applies to Fountain Beverages at Burger Kings. Please note that this offer does NOT apply to Fount Beverages purchased as part of Kid's Meal or Big Kid's Meal. You must call from your home residence telephone within 48 hours of receiving this offer. Limited to one per household while supplies last. You must be 16 years or older to participate. To report any problems or for any questions you may have regarding this survey, call toll-free 1-800-454-9141. Thanks for helping us serve you better!
After you call 1-800-749-8831 to take this survey, we will ask you to record you name and address. We will send your $5 to the address you provide no later than 6 weeks from the time you complete the survey. Burger King employees, and their family members and all persons living in the same household are excluded from participation.