Due to the interactive nature of the StackExchange sites it would be nice for less active users to receive e-mail notifications whenever an answer or comment is posted, both for questions asked and questions answered. This has already been discussed in the following answers:
One alternative posted at https://meta.stackoverflow.com/a/270410/1283667 (which was unfortunately down-voted by someone) is to use the Android app which will display the notifications very quickly. But I don't think this alternative would work for everybody.
Another alternative is to use the new Chrome browser notification feature to notify the user when a new answer or comment is posted to a question asked or answered. This would probably not work on all browsers but would be available on almost all desktop and laptop devices used by the Stack Exchange community.
Can we consider these and/or other alternatives to enable all users to receive instantaneous notifications?