It has been my experience that only a very very low percentage will hatch. This is caused by the ruff handleing they sometimes encounter dureing shipping, i.e., shaking, dropping, airplanes, trucks, hands, conveior belts etc...
If the cell is simply loose, moves from side to side as you candle and roll the egg, it has a 50% chance, though the chick , if it hatches may not survive.
Now there is also a more extreme, to the point of where the cell actually ruptured, these are toast!
You can quickly identify these when precandleing (which I highly recommend on shipped eggs)
The air from the cell will be floating all threw the egg, either in a big ball or in tiny bubbles. You can try these if you like, but they are not going to develop.
I am so glad you brought this topic up.
So often buyers will accuse their sellers of shipping infertile eggs, when actually, shipping damage is to blame! If everyone would check(candle) their shipped in egg on arrival, then a lot of the false accusations would stop. As mentioned above, cracked or broken is not the only type of damage eggs can get. Infact, that rarely ever happens, what you have is the #1 type of shipping damage.
Hate to hear you got some shook up ones though!
Aubrey