The U.S. Postal Service issues more than 40 billion stamps a year. Many never make it to the mailbox. Commemorative stamps, which honor anniversaries, people or events, are saved by collectors. A recent survey found that the Elvis stamp is king. Here are the most popular keepers:
1. Elvis, issued in 1993
124 million saved
2. Wildflowers, 1992
76.2 million
3. Rock & Roll, 1993
75.8 million
4. Moon Landing, 1994
47.9 million
5. Civil War, 1995
46.6 million
Source: United States Postal Service