It is always interesting to speculate on future winners and losers in the stamp market. Philatelic popularity is ever changing. In 1900, foreign postal stationery cut squares were a serious specialty that looked likely to continue in popularity. Today, almost no one collects them. In 1950, US precancels were avidly collected; today there are few fans. In 2000, numerically graded “perfect quality” common stamps were the rage. Now, after serious losses, collectors see them as the marketing sham that they were. Decades from now I think the biggest loser will be US First Day Covers. FDC’s are a relic of the 1950s when they first gained popularity. They were a nice adjunct to a regular US collection largely because the United States issued so few new stamps (In 1953, the USPS new issue total was three).
Collectors looked for ways to expand their appreciation of new issues, and First Day Covers were one way (as were plate blocks). Now with hundreds of issues per year, FDC collecting is the hobby of only a dedicated few (and those huckstered into it by mass marketing mail order houses). The resale value of FDC’s is low and declining, especially lately. In large units, we struggle to get 15