You will want to have other methods of connecting with the people who have chosen to join your list. I have found that inviting them to follow me on Twitter, become my friend (or fan) on Facebook, and to connect with me on LinkedIn and FriendFeed are excellent ways to stay in touch. There are several ways this can beneficial to your business.
Email deliverability is not what it should be these days. Your email may never show up in your prospect’s inbox, or it could get lost among the many emails they receive each day. By sharing what you have to offer on social networking sites, you can remain ‘top of consciousness’ for them in a more substantial way.
I recommend sending a solo email that tells them exactly where they can find you. Also, include the direct links to these sites in the P.S. of your email. Even if someone would choose to unsubscribe from your list at some point in time, you would maintain your connection with them for the foreseeable future.