Automatically register users with comments

There are a number of functions you can use:

• register_new_user
• wp_create_user
• wp_insert_user

The first function being the most simple to use and the last function gives you many more options – it depends what you want to do.

You can create the new account when the comment is posted using the comment_post hook. You will first want to get the comment using get_comment(), passing the ID from the comment_post hook, and check to see if the email is already registered on your site,

Just make it very clear to the user that you are creating an account, as per Tom’s comment on your question.