Actually, the Email marketing & Social Media the element which you could not separate.
Base on the research, I found that the most of people in US spent at and hours a day for check their email in the morning and even both daytime.
Also, the most of people in US spent at lease 15 minutes a day on social media platform such as Facebook and Twitter, and else.
See, Facebook allow to place CTA feature in your Fan page because it was connected with Email and Social Media.
You should use Email marketing to improve more social media present, and use social media to build bigger list of your subscribed. it is loop process....
The both is using in purpose of building relation with your audience, relationship worth billion dollar..