This might have been a salesman's trade card sample, with blank space on the bottom for placing the name of a store or brand name of an item such as soap, tea or coffee. The back of the card is blank, and that is usually reserved for an advertising logo and a description (and high praise) of the product.
At 3 x 5 inches, it's also possible it was promoted as a premium--a collectible card tucked into a canister of tea, flour, or coffee.
