Subscribe existing users to a new taxonomy term

I have a site that allows users to subscribe to blog posts based on a 'Blog Categories' vocabulary. If they are subscribed to a term in the vocabulary and a new blog post is created with that term assigned to it, then users will receive a notification.

Is there a way to automatically subscribe existing users to newly created terms in that vocabulary? At the moment, it seems like I have to have each user manually subscribe to the new term via the Subscriptions tab of their user page (or do it for them as the site admin).

A related question in case I have to do this directly in the database: to create a subscription to a taxonomy term for a user, would I just have to create a new record in the 'subscriptions' table - module = 'node', field = 'tid', value = term id, recipient_uid = uid of the user? Are there any other tables that are affected when a new taxonomy term subscription is created?