@jonkokko This scam has been going on in one form or another since at least early 2013: http://www.708media.com/scams/facebook-free-macbook/
Whether it's arriving by phishing eMail, smart-phone popups, rotating ad-servers on legitimate webpages, or whatever, it's still a scam. Part of the scam is simply to get users to visit or click on something to raise its rankings and further spread the scam.