I got in on a similar dealio a while back. The Playboy comes wrapped in plastic. The front is blacked out (plastic) and the back is clear, but they always put some paper ad between the back cover and the plastic, usually some Franklin Mint junk. So unless you knew that that's how the Playboy comes, you wouldn't know it was Playboy. Just a heads-up for those who are worried about their privacy!
Be warned though that sometimes, they will put a "Playboy" ad/offer in place of the Franklin Mint junk, and in these case, it will be plainly obvious what magazine you are subscribing to. Doesn't happen every month, but it does happen occasionally. If you're a subscriber to PB, you'll know what I'm talking about, with the envelope containing the upper torso picture of Kelly Gallagher .