It's fairly common to see users come to a SE site, ask a question, and never show up again. This is despite the fact that they got good answers from other SE members. Naturally if the question asker doesn't return they will never choose a correct answer.
What I propose is that these users get an email letting them know that their question has answers and they should return to the SE website and review the answers and choose a correct one if they feel any meet that criteria.
Criteria for sending the email:
Question is at least 3 days old
There is at least one answer
The user has only logged in once (when asking the question)
It is automated
Goals of this feature:
Gets users to come back to the website hopefully encouraging them to continue to return
Helps to increase rep which encourages members to participate
Increases rep which is helpful in newer SE sites that needs members to reach the magical 2k rep mark needed to community moderate
It's kind of frustrating to see so many drive by question askers ignore their questions. Hopefully this will help to mitigate that problem.