In my experience, it's only really the end cap displays that are bought and sold, rather than the inner aisle space. For instance, Nabisco or Keebler/Kellog's (

In my experience, it's only really the end cap displays that are bought and sold, rather than the inner aisle space. For instance, Nabisco or Keebler/Kellog's (though they have recently moved out of DSD) might pay to get a permanent end cap space contract across a chain with certain stipulations (must be facing the cash registers, in the front of a high traffic aisle, etc.) and then they'll merchandise that space with whatever their sales items are. To compete with Walmart, many retailers eschew selling this end cap space anymore, instead electing to have vendors/suppliers put that budgeted money towards decreasing the overall cost of goods sold. Instead, retailers plan the endcaps themselves based on seasonal focuses and promotional pricing. The inner aisles are usually planogrammed (the retail nomenclature for the diagram of where stuff should be, height of the shelves, how many facings, etc.) according to the priorities of the category manager i.e. the person in store corporate offices responsible for that particular product group. You'll notice that categories and subcategories inside of a grocery store are organized into shelfing sections of multiples of 4 feet (most commonly). Each of these sections is assigned to a category manager, and managers usually have multiple categories. So Category Manager A might be responsible for 16' of soup in one aisle and 20' of canned vegetables in another aisle. (The layout of the aisles and which categories go where is a separate discipline referred to as "Space Planning"). So this space isn't necessarily "sold" per se, but the category managers usually work with what's called a "category captain", an individual or team that represents a dominant brand in the category, and they influence the planogramming process. They are supposedly unbiased and are merely providing expertise and insight on their respective industries, but that's a pretty naive view as they clearly get to advocate for their products directly. However, the strategy of the grocer will determine how much influence they actually have. Wegmans, for instance, has a strong focus on private label so Wegmans brand products tend to get the most shelf space no matter what.