It really depends on their marginal costs of serving single customer. I would guess that for text content producers, it's costly to produce content and cheap to

It really depends on their marginal costs of serving single customer. I would guess that for text content producers, it's costly to produce content and cheap to show it. Then it makes sense to price discriminate (to show ads / ask for subscriptions as much as you can), but not refuse service to anyone able to bring any kind of revenue, even accounting second-order effects such as more exposure. You can still see cases where publishers choose to not show stuff to anyone, but that's an artifact of imperfect ability of the publisher to discern between customers that would pay and the customer's that wouldn't -- they don't want to make a mistake to disincentivize someone able to pay from paying. You can see when they try and allow access from FB shares for example. This makes it completely different from asking actual people for free work: person's price of time is expensive and it's rarely useful to give it away.