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. It has been a long 23 weeks. I worry about bothering people.

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.