Once you have your blog/website established it is very important to have a way for your readers to give you their email address because blogging is about relationships. You want people to come back to your blog/site to get to know you better, BUT you will need to remind them to come back. You do this by building a list.
There are several ways to build a list. I LOVE Awber! Aweber allows you to use a popover on your page which will multiply your list sign ups, you can also use it in your sidebar as I do. When someone signs up for our free mini-course they are added to our mailing list. There is a lot to learn about auto-responders and mailing list, but we are just touching the surface today.
When you have a mailing list you can also let them know when you have a new product or are running a sale. Just be careful not to abuse your list and bombard them with tons of spam.
Using your mailing list wisely will help to keep your name before your readers and build trust.
Here are some articles that will help you with an auto-responder:
This post is linked over at Legacy of the Home.