Not by Wal-Mart, but by Woolworth's:
Food suppliers say they are struggling with the new Australian owners of Woolworths and Foodtown, who are using hardball tactics in New Zealand.
The New Zealand Herald said Woolworths Australia had threatened to ban suppliers' products or downgrade their position on shelves unless it gets discounts of 10 to 15 per cent.
The usual terms were around 5 per cent, suppliers spoken to said.
There was no option but to accept demands because of the company's market share, meaning suppliers' margins were getting extremely tight.
One company said it may have to shed jobs and prices would have to go up, but several others said Woolworths' tactics included not accepting price increases from suppliers.
<more> http://www.stuff.co.nz/stuff/0,2106,3689305a11,00.html
Thus begins the downward spiral ... if the companies give into Woolworth's demands, nothing good can come of it. Certainly consumers who shop at Woolworth's will see 'lower prices' on the shelves, but they will pay a much higher price everywhere else, as supplies shed jobs and degrade their products to meet these ridiculous price demands.