OpenAI's way of retaining users is called a retention offer, which is a pretty common strategy in subscription services. For example, when I subscribed to Adobe's full suite, if I tried to cancel, they'd immediately offer me a discount. If you insist on canceling, sometimes they'll give you an even more aggressive option, like offering a free month. Essentially, this works because the marginal cost of traditional online services or (streaming) media is close to zero. Service providers would rather 'earn a little less' to prevent 'losing a customer,' maximizing total revenue. It's a form of 'price discrimination.' However, in the AI field, marginal costs are usually more significant. Every user request directly translates into GPU computation and electricity costs. So when OpenAI still chooses to offer a free month to retain users, it often means they have a strong belief in the long-term value of retention (though fierce competition could also be a factor).