Sounds good, but the response by the consumer upon finding the Coke being sold out (or one that Coke fears) would often be: "The machine ran out of Coke, so I won't get anything", or ever more dreaded by Coke/CCE: "The machine ran out of Coke, so I'll get a Pepsi from the machine next to this one". The same for Pepsi.
Now, if Coke/CCE (or Pepsi) researchs out the average sales of each product in each area, then they MIGHT find EXACTLY how many slots they need for each product, with the possibility of freeing up slots for reintroductions/new products.
I stil maintain that BOTH Coca Cola & Pepsi Cola have reached such a point of market saturation (how many people have tried neither but will start buying either based on ads?) AND product prefference (Will a Pepsi buyer switch to Coke just because of an ad?, and visa versa? I had one Boss where if there was no Coke at a Restaraunt he'd order an Iced Tea instead, forget Pepsi for him, no matter how many ads they have) that I think both are throwing away a lot of money with their ads for their colas.
Now, ads for the cola variants of both, & other products will do MUCH more good. I think Mello Yello falls in this class.
Life is too short to drink crummy sodas...