Our local grocery duopoly (Australia) not only charge for placement, but are now demanding that suppliers pay for transport between the supermarkets central and regional distribution warehouses, but will only take delivery centrally.

That's on top of some products (eg bread) being actually stocked on the shelves by the supplier.

Basically supermarkets are just local distribution warehouses with everything else either paid for by the supplier or the purchaser (eg shelf picking/checkout).

can donate* for better placement