Hi everyone, I have some questions for experienced sellers as I'm not sure how to go about this situation. I have hatched eggs from several other breeders, have messed up a lot and learned a lot along the way and now I think I'm doing really well and have started hatching eggs from my own chickens (previously I didn't have any roos so wasn't able to). I have been getting really good fertility from my girls and recently started selling their eggs for hatching as well (for cheap -- only $1 per egg, since I'm still relatively new at this and they are just barnyard mixes). I store the eggs under my bathroom sink -- I have them titled, and turn them to tilt the other way about three times a day. I have learned which girl I get poor fertility in, and which girl's eggs just don't seem to develop.. and I don't include those girls' eggs for sale (unless requested), nor do I include eggs from the newer layers who I haven't been able to check for consistent fertility for a long period of time.. I don't wash the eggs, and I don't sell dirty/poopy eggs. All of the eggs are dated in pencil. I recently sold 22 eggs to someone who just bought an incubator. The eggs were all between one and six days old. She had requested a few of my chocolate eggs, which I told her I hadn't previously had a good hatch rate with (fertility fine, but weren't developing), but she wanted to take a chance, so I gave her four extra eggs to make up for those ones in case they didn't work out. I had just had a good hatch born the day before I sold these eggs so I was confident these would work out (minus the chocolate eggs which I wasn't confident on). It was an hour for me to drive them to her but I individually wrapped each egg in toilet paper and wrapped the cartons in bubble wrap so it was an easy ride for them. It's day 21 since she got them and she wrote me to tell me that none were viable. I would have chalked it up to inexperience but she says that the other eggs in the incubator are all developing (I am guessing mixed hatch dates or they would have been born already). She thinks mine were not fertilized. I had nine roosters to 21 girls (a bunch of those being chicks that the roos ignored), so I can guarantee they were fertilized -- I watch my girls get bred. I had put the exact same hens' eggs in my incubator literally the day after I sold those eggs to her -- and I gave her the newest ones, so mine were all 6-10 days old -- and 61 out of 74 of mine were viable at day 7 of candling. Anyways.. I didn't tell her to begin with that I don't guarantee hatching eggs, so I told her I'd give her another 18 for free. Maybe not the best protocol in the long term since some people are not honest and obviously if someone order a huge amount of eggs I couldn't just go around giving away dozens of eggs all time for free when there are so many variables to hatching eggs.. Anyways.. I don't understand why my eggs didn't work out but the other ones are fine. Is there something I can improve on? What happens if her next ones don't work out? She wasn't angry and I appreciated the feedback.. I'm just disappointed for her and for myself. I thought I was doing pretty good. Tips and advise appreciated! Should I include a written disclaimer in every carton of hatching eggs?