Here's how to get endless free Postmates deliveries for the rest of the summer in NYC and The Hamptons

Delivery startup Postmates is offering one very impressive, expensive-sounding promotion to New Yorkers:

For the rest of the summer, every Thursday through Sunday, they can use Postmates to get an unlimited number of items delivered to them for free either in the Hamptons or in New York City. Postmates is hiring a full-time staff all over the Hamptons to bring you things like on-demand ice when you need it for cocktails or a sandwich when you're hungry on the beach.

The deal lasts through Labor Day, and there's only one catch: You have to download a helicopter app called Blade to unlock the unlimited deliveries.

Blade is an on-demand helicopter and sea plane service based in New York City that can fly you to places like Fire Island, Mohegan Sun, and Montauk in 30 minutes flat. It costs about $595 per seat depending on when you fly and who else books a seat on your chopper. Blade recently raised $6 million at a $25 million valuation from investors like Google chairman Eric Schmidt and IAC's Barry Diller.

But you don't actually have to use Blade to get unlimited free deliveries from Postmates. All you have to do is this:

• Download the Blade and Postmates apps
• Open Postmates
• Go to "Promotions" and type in the word "Blade"
• Do this before Monday August 2 at 12pm ET
• You're done. Get unlimited free Postmates deliveries in the Manhattan and Hamptons area through Labor Day 2015 every Thursday through Sunday.

Postmates, which has raised $138 million, is footing the entire bill on this and it's apparently happy to do so because it likes Blade's demographic. Blade's average user is 31 and it skews 45% female according to its CEO and founder, Rob Wiesenthal. Wiesenthal says this is significantly younger than the average helicopter rider, which skews mostly male and the average age is 45.

So, does the promotion really work?

Yes, yes it does. I tested it out this morning. I downloaded both apps for the first time. Having never flown Blade, I opened up the Postmates app and typed in the code. Postmates told me the code was accepted. I then promptly ordered a bagel for delivery. Postmates told me my order would normally have cost just under $10 to deliver, but thanks to my promotion, my bagel's delivery would be free.

Here's the email Postmates is sending to its users to promote the Blade deal.

BLADE gets you to the Hamptons in as little as 30 minutes. Now, we're teaming up with on-demand delivery leader POSTMATES for the ultimate convenience-anything brought to your door in minutes.

Whether you crave cookies from Levain?,? Mexican from The Blue Parrot, a steak from The Palm-or even if you just need some ice to keep your guests' cocktails cold. You decide what it is, and Postmates will bring it directly to you, at the touch of a button.

Simply download the POSTMATES app and enter the promotion code BLADE to enjoy unlimited free delivery through Labor Day. That's right. Hamptons and Manhattan delivery is on us for the rest of the summer, every Thursday through Sunday.*

*You must download the Postmates app and enter the promotion code by Monday at 12PM.