Extremely scarce card type featuring a Hall of Famer, the Successful Farming cads advertise an Iowa-based magazine.  It is theorized that the cards bearing the Successful Farming advertisement on the reverse were promotional cards, and that the cards distributed in the magazine were actually blank-backed, which helps explain the rarity of the back.  Just 49 Successful Farming cards have been graded by PSA and SGC combined, and this is the only example of Hall of Famer Zack Wheat's card that either have seen.