Facts are facts: We're living in the digital era. And while it's projected that we will send "376.4 billion daily e-mails by 2025," per Statista, snail mail is still the preferred method of communication for some people. But you can't make an omelet without breaking a few eggs, and you can't send a letter without some stamps.

That's why the United States Postal Service (USPS) issues Forever Stamps. These "first-class stamps are non-denominational," and the first ones were issued back in 2007, according to Liveabout. And some pretty gorgeous stamps were previously available in USPS' postal stores.