From USA Today's article on the service:

*It's going to generate a lot of excitement," says Janet Klug, president of the American Philatelic Society. She supports anything that brings people back to snail mail, which is "going the way of the dodo bird."

But don't expect that Aunt Edna or Fido stamp to appreciate in value. Anyone can make a PhotoStamp, anytime they want. And, at almost $1 apiece, stamp collectors are unlikely to buy into them, Klug says. They are "very thrifty individuals."*