My opinion is that responses to a person's question, especially if it involved some research on the part of the responder, should be public. I would like to see how others approach a problem and find documents or other information. When a moderator says that responses should be private, I don't get to learn from others' search strategies.
How the original requester words their request for information - I've seen too many times that the person is using please and thank you in their original post, but then they neglect to include what they already know about the ancestor they are researching, or neglect to include a list of what records they have already found. Including this information is being considerate of responders' time, since that means the responders don't have to go out and find information that the requester already has.
Thank you posts - These do serve a function for everyone. It tells all readers that the requester has already gotten the answer they are looking for, and it keeps additional readers from responding, whether publically or privately.
Lak/Lok/Liak/Lock and Kalon/Kolon in Zagare/Joniskis/Gruzdziai, Lithuania
Lak/Lok/Liak/Lock in Plunge/Telsiai in Lithuania
Rabinowitz in Papile, Lithuania and Riga, Latvia
Trisinsky/Trushinsky/Sturisky and Leybman in Dotnuva, Lithuania
Olitsky in Alytus, Suwalki, Poland/Lithuania
Gutman/Goodman in Czestochowa, Poland
Lavine/Lev/Lew in Trenton, New Jersey and Lida/Vilna gub., Belarus