We grow our email list via social media marketing (which could be considered viral):
1) Create an effective profile. What do I mean by effective? Use a real photo of yourself and your real name. Include your location and a good bio--complete, up-to-date and with all contact information.
2) Offer events. A great way to add targeted subscribers is to hold an event such as a teleclass. Invite your followers and friends and direct them to a sign-up page specifically for the event. Let them know that in addition to signing up for whatever the event is, they will also receive a complimentary subscription to your e-zine or other valuable information.
3) Join a Ning network or create your own. Ning is a platform which allows people to create their own social networks online. Anyone can create a network for free around a specific interest. This is a great tool for getting in front of your niche or target market.
4) Sync your newsletter broadcasts with Twitter. If you use an email list service such as AWeber, you have the option to automatically tweet a link to your newsletter when the broadcast is sent out. Just choose Syndicate and Twitter Update.
5) Place an opt-in box on your Facebook profile. This is something I explain how to do in detail in my free e-course. The Profile HTML application in Facebook allows you to add your opt-in box for collecting names and emails very easily. This way you can capture new subscribers right from your profile.
6) Use social bookmarking sites. Social bookmarking is a way for internet users to search, organize and store bookmarks of web pages. Have a way for readers to submit posts they enjoy to bookmarking sites (Digg, Delicious, StumbleUpon, etc.) right from your blog. This is a nice way to drive traffic to your site when others come across your bookmarked site.
7) Feed your blog posts to sites automatically. Facebook, Twitter and LinkedIn all have tools that will post your latest blog posts on their sites as soon as they are published. This keeps you consistently on others radars.
8) Be helpful and participate often. The best advice I can give for spending time on social sites is to give, give, give. You do not have to spend exorbitant amounts of time there, but when you do use them, offer suggestions, advice and tips. Create conversation as well as join it. People will get to know you this way and want to seek out more information about you.