[buymycards]

These are very interesting. I am stealing this from the Benjamin and Eckes Non-Sports Price Guide:

"The machine printed backs with ads for the 240 Pictures were given away in other GUM Inc products to attract buyers to the HOW cards. They were also sent to schools for distribution to students and were the "cargo" in Bowman's famous "balloon barrage" of Philadelphia."

Pretty cool to come across these three backs.

Rick