Facebook has more than 1.44 billion users, which makes it a hacker's paradise for posting scams. Even if only 1% of users fall for the scam at first, that's still tens of millions of potential victims. And once they get hooked by the scam, it's more likely some of their friends will as well, followed by those friends' friends and so on.
Tell me if this sounds like a good deal to you: Spend $110 at Kroger, one of the nation's largest grocery chains, and get $100 in free groceries. All you have to do is share that same coupon on your Facebook page. Here's a photo of the coupon. Do you notice anything wrong with it?
Sure, this looks like a real Kroger Coupon. It displays the company logo, there aren't many obvious typos (but there are a few) or other telltale signs of a scam. However, I noticed right away the absence of a barcode. These days every coupon features a barcode to be scanned at checkout that automatically credits the coupon's value to your total.