Cold messages to people in my field, do they work? - what worked for you?

A friend suggested informational chats and I do not know how to ask. I do not usually post, so bear with me. Some people reply with short answers.

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

Follow up with a thank-you and a short update. One of my chats led to a referral a month later.