Tap, I have had many shipped eggs, with both successes and failures. My conclusion is that given fresh, well-packed eggs from fertile birds, the biggest factor in failure is likely how they were handled during shipping. The more sorting they go through the harder the equipment is on the eggs. Packages go through a lot of automatic sorting and handling. I find that even when the eggs start they often quit, leading me to believe that the fertilized eggs are affected in some way, causing failure to develop normally.