This article will tell you pretty much what you need to know...
Quote:
"ICS sells its customers -- most are not stamp collectors -- an introductory set of stamps for about $13. Then, like the Book of the Month Club, ICS signs them up for one of its "clubs" -- Elvis, Marilyn Monroe, the Beatles or John Kennedy, for example. The customers then regularly are offered sets of stamps from places like the Central African Republic, Guyana, Gambia, Dominica and Sao Tome."
https://www.washingtonpost.com/arch...0e07cbee98e/It is not uncommon that some of these 'stamps' have never been within a thousand miles of the 'issuing' country. Considered as 'manufactured collectible' by many, they usually have little value. If you can find any used on an actual used piece of mail, they can carry some value.
Don