I am always the skeptical one, but just because it says the publisher's name at the bottom doesn't mean it's the actual company. There is a hearstmags.com (without the additional info on the link provided), but the price there is $15 for a year. I can't find anything on their actual site for the $5 deal. I did email the company to make sure it was a legit offer before ordering. I'm waiting on a response.
OP, where did you find the $5 off link? Was it from an email directly from the company? If so, then it should be fine.