From BR Bullpen

Fleer was a bubble gum company that eventually moved into the sports card business. Their first attempt to produce baseball cards was in the early 1960s, when they signed Ted Williams to a contract to produce cards with his image. They had little success in attracting other players, however, and eventually abandoned the effort. Topps, which had acquired it chief competitor Bowman in 1956 had signed exclusive agreements with most players, and maintained a virtual monopoly in the market through 1980.

In 1981, Fleer along with Donruss released baseball card sets that broke Topps' longstanding monopoly. In order to get around an earlier Federal Trade Commission ruling that it was legal for Topps' contract to specify that no other competitor could sell cards along with gum, Fleer sold its cards with a sticker. Eventually, as the baseball card hobby boomed in the 1980s the companies would stop including any type of additional merchandise or inducements and market the cards as stand-alone products.

Fleer remained as an independent producer of baseball cards until 2005, when the company became financially insolvent and began bankruptcy proceedings. Competitor Upper Deck acquired the Fleer brand name, and continues to produce Fleer branded cards today.