Tech Insider/Jeff Dunn
That offer should look familiar, as Samsung ran a similar promotion around the time the Galaxy S7 and S7 Edge launched. Here, though, the deal applies to the Galaxy S6, Galaxy Note 5, Galaxy S6 edge, and Galaxy S6 edge+, in addition to those two newer devices.
You can check the fine print for full details, but to activate the deal, you'll have to buy (or lease) one of the above phones from a supported retailer - including the four major carriers, Walmart, Best Buy, and others - before June 20, then fill out an offer claim form by June 30. You'll also get an unspecified "Oculus content bundle" with your purchase.
All told, this is a good deal for VR-curious people in need of a new phone. It's not controversial to say the newest Galaxy flagships are two of the best phones on the market, and last year's models remain plenty decent in their own right. The Gear VR goes for $100 on its own, and while it can't touch something like an Oculus Rift or HTC Vive (and could use more compelling apps), it's a legitimately effective step above Google Cardboard.
The only hangup is that you might have to wait a bit before your claim is fulfilled - at least if the last promotion is any indication. A surprisingly wide array of forum posts floating around the web have noted shipping delays in the aftermath of the last deal, with some waiting a couple of months before their headsets showed up. Samsung, for its part, says it is still working to get those remaining Gear VRs out as soon as possible.
Regardless of those concerns, and regardless of Samsung's rationale for offloading so many of these for cheap, a free virtual reality headset is a free virtual reality headset. If you're grabbing a new Galaxy anyways, you might as well take advantage.