Is it competition, or is it pressure from Wal-Mart?
I can't imagine any of the majors risking their products being pulled from Wal-Mart's shelves for months at a time.
That happened to my wife's former employer in the household products industry. Wal-Mart asked them to lower their prices, the company declined, and Wal-Mart said, "Enjoy a year of no sales at our stores." The company sent a team of negotiators to Arkansas and got product back on the shelves in a few months.