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

I sent 8 messages on a professional network and got two replies. I worry about bothering people. Did any turn into leads?

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

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