Should we sunset the free tier entirely, or keep it as a loss leader?

I've been running a free tier for two years, and I genuinely can't tell if it's the best thing I ever did or the most expensive mistake I keep renewing.

The case for keeping it is real. It's my top of funnel, my word-of-mouth engine, and my best source of honest feedback from people who have no financial reason to flatter me. Some of my best paying customers started free, fell in love slowly, and upgraded when the moment was right. Without the free tier, I'd never have met them.

The case against it is also real. It costs me real money every month — servers, support, and most expensively, my attention. A large chunk of my support tickets come from free users asking about things they'll never pay for. And every hour I spend helping someone who will never convert is an hour I didn't spend on the people who actually fund this thing.

The part that scares me most is that I don't actually know my free-to-paid conversion rate with any confidence. It might be 2%. It might be 8%. I've never measured it properly because I was too busy being generous to look.

Have you killed a free tier? Did revenue go up, go down, or stay flat? And if you kept it, did you ever regret the decision — or was it the thing that quietly built your whole business?