I can't tell you how many times I have accidentally left raw chicken in the fridge past the 1-2 day guideline. I admit, as long as in smells okay, I have cooked it for dinner. So far,I've never had an ill effect. As I type this, I have a pack of 3 breasts that have been in the fridge since I bought them 5 days ago. However, the "sell by" date is still two days from now. Are supermarket refrigerators colder than the average home fridge? Is that why they would be able to keep the chicken in their refrigerated section for so long?