Cold messages to people in my field, do they work? - first time posting

I sent 7 messages on a professional network and got two replies. I have been trying to stay organised about it. I want advice, not a job directly. What did you ask?

I asked what they wish they had known at my stage. People enjoy answering that.

I wrote three short lines: who I am, why them and a small ask for fifteen minutes. About one in four said yes.