Subscribe to a post's comments without posting a comment yourself

Question

I've seen a few plugins (subscribe2, subscribe to comments) that allow people that have commented to receive emails containing follow up comments.

What I want to do is slightly different. I want to post to have a 'Subscribe' button. Clicking this would then allow the user to receive by email subsequent comments to that post. They would not need to post a comment themselves.

Is this possible with a plugin, code or a mix of the two?

Answer 1

Subscribe To Comments Reloaded allows subscribing without commenting. It uses a link instead of a button, though.

Screen shot:

It shouldn't be too hard to customize.