I came across an interesting decal on the inside of a CSS-8-64, giving the stocking percentages based on demographic.  I haven't seen one before, its pretty beat up, but you can read all of it.  Here's what it says:
STOCKING GUIDE 
FOR 
VENDING MACHINES
IF THE CUSTOMERS          OF YOUR  MACHINE ARE: | TRY STOCKING IT          THIS WAY TO  INCREASE SALES: | 
 | 
| A - MALE | Coca-Cola....................66% Sprite..........................14% TAB..............................4% Fresca..........................3% Fanta Flavors & Mr. Pibb 13% | 
| B - FEMALE | Coca-Cola....................60% Sprite..........................16% TAB.............................11% Fresca..........................3% Fanta Flavors & Mr. Pibb 10% | 
| C - YOUTH | Coca-Cola....................62% Sprite..........................16% TAB..............................2% Fresca..........................3% Fanta Flavors & Mr. Pibb 17% | 
| D - BLUE COLLAR | Coca-Cola....................64% Sprite..........................16% TAB..............................6% Fresca..........................3% Fanta Flavors & Mr. Pibb 11% | 
MORE SALES MEANS MORE DOLLARS