Just want to say a couple things....
Those of us who have been around know a few rules about selling/shipping eggs. This is just a cover all so new sellers might pickup something they might have missed.
selling and packing:
1) Please please do not wash the eggs you sell... this invites all sorts of problems for hatching them.
2) When packing make sure they can not bump each other. packing in the carton is fine but put some packing inside the carton to prevent them smashing against each other.
3) pack the eggs in the middle of the box with good solid packing materials all around the eggs. if you pack the bottom and sides but not the top the PO will undoubtedly smash in the top....
4) always test your eggs by incubating your own eggs and understand that in the winter your rooster can go sterile by being to cold or etc. (btw you don't have to hatch chicks just incubate them until you see growth though I hatch them and sell the chicks locally)
5) listen to your customers as sometimes they really do get all infertile eggs. It happens even to the best of us.
Include a instruction sheet that says what temp/humidity etc for hatching. most of us know whats what but the new hatchers are the ones who have the most problems and have the most need for clear concise instructions.
buyers:
1) Understand shipped eggs are always going to have issues due to the PO handling and etc.
2) Sellers can not say if the egg is fertile or not. They can test and have a good idea of fertility rates but there is no magic sign that says this egg is fertile and this egg is not. least not without destroying the eggs
3) Contact the seller if there is any problems most will work with you and help answer any questions you may have as sellers want you to have a successful hatch.
4) Always test your incubator for a few days, move the thermometer around as you might have a hot/cold spots or the area in the home might flux to much to maintain a good solid temp for hatching. use at least 2 different thermometers.
5) Always do a "eggtopsy" if you find that a lot have developed but died in egg then you need to check your incubator/thermometers, if they have a "scrambled" yoke that is due to rough shipping. (When I hatch I always keep a record of # or clears # scrambled # developed but died etc... this helps me figure out what the problems were)
6) Winter hatches are lower on fertility then summer hatches so for first time hatchings try a spring summer batch to learn the ways.
Ok thats off my box..
Just so you know I buy and sell eggs, I have had all the packing errors i listed above with eggs shipped to me. And I have had my own batches which I test in my incubator (I have it running almost all the time) suddenly go with no fertility. I sometimes wonder if the rooster suddenly goes sterile for some reason or another... will have to research that.
last hatch from bought eggs. 17 total eggs, 2 stopped development in egg, 2 hatched, rest were either scrambled or clear infertile.
Oh and the broken air pocket eggs sometime DO hatch so don't give up on them until after week 2. They tend to be slow developers.