Old vintage postcards display historical significance, revealing details about the landscape of the time while sustaining an antique appeal. Postcard collections can bring a sense of personal satisfaction or produce some extra pocket change. The profit depends solely on the value of the postcard, which is determined by a combination of factors.
Assess the value of your postcard by researching online (see resources), or with companies that specialise in such appraisals. The value is determined by the age, condition, topic and rarity of the postcard.
List the postcard on online auction sites. Follow the site's instructions on how to properly list the postcard. Make sure your price is comparable with similar items on the site. Other vintage postcard sites will offer to buy the postcards directly from the collector. Communicate with the dealer about how to sell the postcard to the site. The dealer may request a description and/or photograph of the postcard.
Take the postcard in to a consignment shop. Find a nearby consignment shop online (see resources) and make an appointment. For antiques such as vintage postcards, the shop will have an "expert" to appraise collectibles. Make sure you have a collection of postcards to take in rather than a single one. Dust and clean the postcards without tarnishing the delicate surface before you take them in.
Sell the postcard at an auction house for truly valuable postcards. Auction houses attract a more savvy crowd, upping the potential to yield a better profit. Find auction houses online (see resources).