Is there a way to cap the number of users that can complete a form? For example, when creating an event and using a Marketo form to register, is there a way to limit the submissions to 30 if the event only has room 30 attendees?
This has been an idea in the community for quite a while. Without a third party tool, for the moment, it is not possible.
some third party solutions using webhooks such as brighthooks will enable you to do this.
otherwise, vote here: Cap Registrations for Events