Has anyone been offered a free iPhone 6S for participating in a test for the iPhone 7?

Just out of no where, I received a message that I was randomly selected to test the brand new iPhone 7. The message appeared on my iPhone 5C. And further, it said if I'd like to join the private test group I should answer 4 questions. In return, I would receive an iPhone 6S for free. Is this offer a valid Apple offer or am i being scammed?