The United States Postal Service's popular first class "Forever" stamp concept has now been extended to postcards. The "Forever" stamp was created several years ago so that you would not have to purchase additional one or two-cent stamps every time the rates when up. They were printed with the word "Forever" on the stamp instead of a value so you could simply use the stamp on first class letters regardless of the current postage rate or how much you originally paid for it.
Now, the post office has introduced a "Forever" stamp in a postcard variety. The stamp has no value printed on it, but does include the word "Postcard". It currently costs 34-cents to mail a postcard, so a 100-stamp roll coast $34 but you can use them "Forever"! Ask for them at the post office.