In your case, commitment is adding their contact information into the modern-day version of the little black book -- your mailing list.

The second reason writers groan when I say mailing list, is that they envision doing a lot of work to build that list. If you don’t want (or don’t have time) to put together contests, newsletters or short stories to entice people out of their email addresses, then here are a few lazy ways to build it:
The easiest option is to have them sign-up to receive a summary of your weekly blog posts by e-mail. Several of the mailing list companies can do this for you automatically. That makes it the perfect low maintenance approach to building a mailing list.
Another option is to have a sign-up for special announcements. Let people know that they will not receive weekly, monthly or regular contact from you, but will only hear from you when you are announcing new books, release dates, public appearances, virtual book tours or other important events. That way people know that they are signing up for periodic advertisements from you about your books. Provide them with a one-time valuable item, like an ebook, podcast or videocast.
Don’t feel like you have to choose just one of these. Mix and match as you like. Just promise me you won’t let them sneak off after partaking of your goods.
