By Amy Feldman

By Amy E. Feldman

PHILADELPHIA (CBS) — How do you know if an online promotion is the real thing or a scam?

More than 40,000 Facebook users shared a post allegedly put out by United Airlines offering to enter all who share a photo the opportunity to be in a contest in which they’ll give away 100 free tickets that could be used anywhere United flies. Which sounds awesome. Except that it’s completely fake. But there are some companies who use social media to promote their brand, including sweepstakes. So how do you know?

First, there are a lot of laws that govern sweepstakes, and in order to comply with them, a company has to have some standard disclosures (all that language in small print that no one reads). So if there’s no fine print — that’s a good tipoff it’s a scam.  All sweepstakes have to have official rules. So look to see the words “Official rules”.  And by law, they have to tell you that there’s no purchase necessary to win so look for the words “no purchase necessary”.  Always Google scam alerts before re-posting lest you get unfriended for posting the fake tip to fly the friendly skies.