Cold messages to people in my field, do they work?

I sent 16 messages on a professional network and got two replies. I have read a lot of threads here and could not find my exact situation. I worry about bothering people. How do you phrase the request?

Thanks for writing this out. I went through something close to it last year, and it got easier once I kept a simple log of every call and form.

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