There's a new summer scent coming in June: The U.S. Postal Service is releasing its first-ever scratch-n-sniff postage stamps.

The colorful Frozen Treats series of Forever stamps depicts frosty ice pops, and the stamps themselves are printed with a scented coating that evokes "the sweet scent of summer," the USPS said in a release. 

Each stamp features two different treats, from fudge pops to fancy watermelon pops to patriotic red, white and blue pops. As Forever stamps, they cost 50 cents now, but will always remain equal in value to the current first-class mail one-ounce price. Starting June 20, the scented stamps will be available at post offices nationwide, but books of 20 ($10) can be preordered now.

Sure, they're a novelty, but the announcement of the stamps appealed to many on social media, especially striking a chord with those of us who collected scratch-n-sniff stickers back in the 1980s.

The post office is smart to break out this mass-appeal innovation, because snail mail just isn't what it used to be.

"The Postal Service has experienced a steady decline in the amount of mail it ships as more of its customers turn away from postcards and letters in favor of email, texting and other forms of digital communication," the New York Times reported in April. "The total pieces of mail it shipped last year was 149 billion, down from 212 billion a decade earlier."

While cool postage stamps won't bring back the days of pen pals and chain letters (on second thought, forget the chain letters), they're exactly what the USPS needs to stay relevant and in the news. Creative stamps help keep collectors interested, and if the buzz on social media is any indication, they are spurring purchases even by those who admittedly don't send a lot of mail.

Alone, they won't save the post office, but they're earning it plenty of good press at a tough time for the service. Here's a look at four other recent stamps that do the same. (And Beatles fans, mark your calendars: A colorful John Lennon stamp arrives in December.)

1. Eclipse stamps that change when you touch them

Scented stamps aren't the first recent innovation from the USPS. In August, the postal service marked that month's total solar eclipse with eclipse stamps, using thermochromic ink to allow letter-writers to change the stamp's image with a touch of a finger. The stamps featured a photograph of a 2006 total solar eclipse taken in Libya by retired NASA astrophysicist Fred Espenak. When pressed, the black disc of the eclipse faded to reveal the full moon.

2. Mister Rogers stamps

A natural side effect of being famous is that some people are going to dislike you. Except maybe for the late Fred Rogers, a treasured television neighbor to generations of children. If anyone out there doesn't like Rogers, whose groundbreaking show ran from 1968 to 2001, I don't want to know that person. The Forever stamp featuring Rogers and his puppet King Friday came out in March. It's bright and lively and straightforward, just like the man himself, and it's proving to be a hit at postal counters.

3. Sally Ride stamps

Dr. Sally Ride was America's first woman in space, blasting off on the space shuttle Challenger in 1983. She famously had to deal with plenty of sexist questions before her famous flight, including whether the flight would affect her reproductive organs and whether she wept when things went wrong. (Answers: "No," and "Why don't you ask the male astronauts this question?") Ride died in 2012 of pancreatic cancer, but her Forever stamp, issued this May, shows the space pioneer smiling gamely in her spacesuit while the space shuttle blazes to life behind her. Ride wasn't afraid to boldly go where no American woman had gone before.

4. Bioluminescent Life stamps using reflective ink

This dazzling sheet of stamps, issued in February, showcases 10 examples of living things that boast the ability to generate their own light. Stamps feature the deep-ocean octopus, the midwater jellyfish, firefly squid and more. The stamps don't quite glow in the dark, but they were made using "a proprietary rainbow holographic material that is highly reflective in white light," the postal service said in a release. "The rainbow pattern imparts a sense of movement and light to the stamp pane." Perfect for those who'd like to be under the sea.