Many times I find many question interesting and I would like to follow them as the answers comes and goes.
When I just startes SO I used to save the tabs and refresh the pages now and then.
Then I discovered that I could mark a question favorite and come back to them by browsing my history. But I often forget a about the questions after a while.
When marking a question as favorite you'll receive updates/notifications on answers and progress along the posts lifetime in your Recent Inbox messages.
Another approach is to make another button as a Follow Question Button.
Sometimes questions aren't particularly good, but the answers coming are worth more than gold. This can make users receive updates/notifications on answers and progress along the posts lifetime in your Recent Inbox messages, but not give the OP undeservedly points.
I bet someone have thought about this before... is there a reason this functionality doesn't exist?