Maybe but I think that is just a seller excuse. My experience has been those eggs that are fresher(meaning people that have more hens laying) and those that don't have to travel too, too far to get to you, hatch out fairly well and those that don't meet the above criteria, don't. If you are going to buy from someone who had a roo and two hens, your hatch rate is likely to be less, since two hens can only lay two eggs a day(unlikely everyday but maybe) and if you get six eggs it will take 3 days to collect then might, if you are lucky, be shipped out the next day and then take two days to get to you, so they are 5 days old before you get them. If someone has just one pair, well, you are just crazy to buy even six eggs from them, let alone a dozen (which I have seen for sale on here). You just have to pay attention to what you are buyihg.