Poster stamps are just a part of 'Cinderella' collecting. Up to 1939 there were perhaps, 500,000 different issued world wide. The 'golden age' was around 1912 - 1920. They were collected worldwide. Most stamp dealers also sold poster stamps as part of their 'new issue' service. Also, most postage stamp dealers prepared and issued their own poster stamps about themselves and their business. As with most 'collectables' the majority are 'common' to 'scarce' but after, typically, 100+ years for some often just one copy has been found. The British Library has the Campbell-Johnson collection of 38,000 different - mainly exhibition - poster stamps
The Cinderella Stamp Club was founded over 40 years ago in London, England, by a small group of philatelists whose collecting interests had diverged from the mainstream of philately into the fringe world of local stamps, revenues, bogus and phantom issues, exhibition labels, Christmas seals and so on - in fact, anything that looked like a stamp but was not a government-issued postage stamp. The formation of the Club aroused wide interest all over the world. People who had been ploughing a lone furrow in what appeared to be a neglected field now discovered that there were many others with similar tastes, and in its first year 86 members were enrolled.
The whole field of cinderellas offers many opportunities for the collector. The major stamp catalogues do not list the majority of cinderella issues and those that do usually confine them to the "back of the book". There is no "cinderella catalogue" covering all aspects, but there are an ever increasing number of specialist catalogues available, many of which have been compiled and published by Cinderella Stamp Club members. Even so there are still many areas where individual study and research is required and the Club's study groups provide a forum for the coordination and publication of members' findings.
Not all Club members collect all Cinderellas but it is possible to identify three main types of collectors: those who collect a specific type of cinderella, revenues or poster stamps for instance; then there are those whose interests lie in all cinderellas from a specific country or area; finally, there are the topical or thematic collectors who find that vast untapped resources exist among the cinderellas. Needless to say, there are many more collectors who do not fit into these categories and whose interests are manifold and eclectic.
Visit www.cinderellastampclub.org.uk for more information