Because I'm in the tech business, I frequently get offers for free subscriptions to tech-related magazines. And even some non-tech ones. Most of the time, I pass on them. For the few I've accepted, after about 6 months they start hounding me to pay to extend the subscription, and I ignore them. When the subscription ends, I stop getting the magazine.

Two years ago, I was offered a subscription to "Electronic Musician". I dabble a bit with keyboards, so I answered the survey and got the subscription. Sure enough, after 6 months or so, I started getting offers to extend the subscription, which I ignored. But when the year was up... the magazine just kept coming. Every month. The label even says my subscription end date was October 2019. But they keep coming. I've had it where a subscription ends and after a few months they send you a freebie to try to entice you to resubscribe. But not every month. I just got the latest issue today. I'm not complaining. But it seems weird that they keep sending it.

Of course, now that I posted this, they'll probably stop next month...

It is actually a common scheme. Magazines make their money selling advertising. Their rates are defined by the number of subscribers. The money they get if you pay for a subscription is much less than what they get for selling advertising.

I got Electronic Musician for a long time. I get at least ten free magazines, mostly from Blue Dolphin. The key is to monitor your credit card bills. Also, be on alert for emails to cancel your renewals.

Never gave a credit card. I answer a few questions (what field I'm in, how many people work at my location, my job title, etc) and I get the subscription.