A common question I get is how I follow up on comments on my blog. I generally will go to the commenter's blog if they have one and leave my response/comments there. But, there is another way of doing it that enables you to communicate which is by email.
If you use Blogger, Go to the Dashboard and click on Edit Profile next to your picture:
Then scroll down the page under Privacy and mark the box SHOW MY EMAIL box.
Put the email address you would like your followers to use. If you are concerned about privacy, you could created a non-identifying email address for this purpose. By default this is email@example.com
Then scroll down to the Identity Section on go to the Email Address field. The email address you use should be input here. I use my regular email addy but again you can create one just for this purpose.
Then click on Save Profile. You are all set to communicate back and forth by email!
P.S. If you have any questions on this please let me know. I wish more people did this!