Baseball cards can be purchased online through a variety of websites that include Dean's Vintage Baseball Cards, Baseball Card Zone, KSG Sportscards and Beckett. Topps, which began including card packs with its bubble gum in the 1950s, was the first maker of baseball cards as they are known today.
Baseball cards were originally part of cardboard cigarette cartons. The Goudey Gum Company first sold a version of baseball cards with bubblegum packages. Baseball cards came to be more lucrative than gum, so sellers such as Topps eventually stopped selling gum with their cards altogether in the 1990s. An estimated 12,000 unique baseball card sets have been released since the 1930s.