What makes a postcard valuable?
There are many varying factors. Some of them are: Age, Condition, Subject Matter, Photo vs. Printed, and even the Postmark. Most of the information you will find here is related to the collecting of topographical images or social history. Postcards are collected for thousands of reasons. Some are topical (Christmas cards, cards featuring Santa, Valentines, Halloween, Black related, alligators, etc…) and others are topographical (regional images, state views, buildings, your hometown, etc…). There are plenty of cards out there. Varying in price from ten cents to thousands of dollars. Age: Obviously the older cards are desirable to a lot of postcard collectors but even cards printed as recently as yesterday are collected. The first known postcard (from my research) was used in Austria in 1869. Postcards made in the USA before 1907 had an un-divided back and the only thing that could be written on the backside of the card was the address. The front of the card usually had a smaller im