To differentiate it from the common playing card used in gambling and entertainment, cards connected with sports are called trading or, often, collectible cards. Baseball cards are the most familiar, although there are likewise football cards, issued when the sport grew to be very prevalent, and collectively sports cards, for other sports games. Non-sports cards deal with cartoons, television, movies or comics. Logically, contemporary cards about cartoon characters are more popular among kids than those of sports, due to the promotion of anime and similar style cartoons.

Baseball cards were originally issued publicly in its tentative forms between 1902 and 1935 that, although of cardboard, were of various sizes and specifications. It was not standardized like those at present, and commonly had misprinted or erroneous contents due to production flaws. The cards were actually just promotional gimmicks for tobacco items, chewing gum and other snacks sold during baseball games, much like the tokens in cereal boxes today. Since the cards included information regarding the players, they soon became more sought after than the products they promoted.

Inasmuch as the cards could not be picked inside the packages, those who find themselves having too many cards of one player exchanged them with the cards on other players. Trading cards hence became the norm and the name. After 1936, the cards were made in uniform sizes and specifications to facilitate trading, and were packaged and sold independently of other items. Baseball cards hence came into their own time as products, and not simply marketing items.

The baseball card as recognized today was conceptualized in 1952 by Sy Berger, who was an employee of the Topps Corporation. Topps was at the time a new entrant into the baseball card field, having first made cards that featured Hopalong Cassidy, a famous Western television character played by William Boyd. Sy Berger created the card that has the name of the player, his photo, facsimile autograph, logo and team name on the front and his biography as well as some personal and game info at the back. The modern baseball cards still follow the identical general format which has become a classic.

Trading cards reached their heyday in the earlier 1990s, but went on a long downslide ever since, along with baseball which is gradually sinking in basketball noise. From around 10,000 US stores selling trading cards, at present there are much less than 2,000 and diminishing. Trading cards have gone down so much in worth that many cards are priced today as it did 20 years ago in modified prices. They have not become collector articles but rather cards to get rid of quickly, accumulating dust rather than value in the basements.

Many owners and hopefuls attribute this unforeseen phenomenon on eBay and similar selling websites. Suddenly, reserved cards are thought of as rare in an area became easily and inexpensively available on the Internet, so the cached ones lost value quickly. Not just for baseball cards but likewise for all baseball or sports cards. It appears sports memorabilia is ceding ground to modern monetary considerations, and more is the pity.