Anonymous sign-ins can be used to create temporary users who haven’t signed up for your application yet. This lowers the friction for new users to try out your product since they don’t have to provide any signup credentials.
Anonymous sign-ins can improve login conversion rates up to 30–80%
Enabling Anonymous sign-ins
You can enable anonymous sign-ins, for your project today from paywall settings, this option only available for tokenized paywalls:

After enabling this option, users will see an additional button “Continue without account” next to Google sign-in:

After clicking this button, users need only complete a one-click CAPTCHA to verify they are human:

That's it! The window will close automatically. When you call paywall.getUser(), you'll see that the user is signed up and their balance has been debited with trial tokens. The only difference is that this user has no email address.

Anonymous users can make API requests like any signed-in user. However, when they want to make a purchase (for example, after their trial tokens expire), they must log in with Google as usual.
If an anonymous user signs out, their session will be saved locally on their device, which means signing in again will restore the same session.
FAQ
Do I need to install the latest paywall script for this feature?
No, it will work automatically with any paywall script version.