Do you have a stockpile of Forever Stamps in a drawer? Isn't it great to know you can use those stamps any time, and they'll be good no matter how much the postage rate may have changed? You can put them on this year's holiday cards, even if you bought the stamps 3 years ago.
At one time, it was called Third-Class Mail. Today, it's known as Standard Mail. In 2017, it will be called (USPS) Marketing Mail. The U.S. Postal Service has proposed a name change for Standard Mail to better signal to customers that this mail is used primarily to market a product or service.