How do photographers go from shooting events for free to getting hired by event organizers?

I’ve been a photographer for about 7 years and it’s been my main source of income for most of that time. Almost all of my work came through word of mouth, recommendations, previous clients referring me, people finding me through someone else. Because of that I never really had to do cold outreach or send emails asking for work.

Now I want to expand and refresh my portfolio a bit, especially with different types of events. So I’ve been thinking about reaching out to event organizers and offering to photograph some events for free just to get access and new material.

My question is mainly about how people turn that into actual paid work later.

When you email event management and offer to shoot an event for free, what usually happens after that? Do organizers sometimes contact you later for paid work if they liked the photos? Or is it more common that you follow up yourself and say something like “next time I’d be happy to cover it for X price”?

Basically I’m trying to understand how photographers usually go from that first free event to getting hired for paid ones by the same organizers.

Since most of my work so far came through referrals, this whole outreach side of things is pretty new to me, so I’d love to hear how others approach it.

EDIT: MY QUESTION WASN’T IS IT MORALLY OK TO DO A FREE WORK. please guys read it carefully