While the save Jack Rabbit part is a complete scam and lie, the magazine you probably will receive. These scams are fairly common where I live, they give you a great cause to give your money into, and in turn they send you the magazine you received, and the company selling magazines makes a huge profit while the chairty, or whatever it might be gets nothing.
Usually this scam is run by college kids in a Wal-Mart parking lot, usually they claim that they are doing a college class for media or sales, and part of their "grade" is going out making a sales presentation selling magazines to raondom people vulnerable in the parking lot, but after the presentation, they hope they have buttered you up enough, and will try to make you buy. It is nothnig but a complete scam, these poor kids are brainwashed into making it sound honest and legit.
Now, I believe they are taking the scam online, as they are probably tired of these college kids havign car doors slammed in their faces, or being cursed at for trying to sell magazines. Definitely do not trust any of these, I know all to well what these magazine companies are up to.