How does social e-mail engage customers?

Social e-mail, relying on the information exchange between 
your e-mail marketing database and social network sites, can accomplish several main digital marketing tasks: improve targeting effectiveness, enhance social media engagement; and eventually drive online sales. 

How can social e-mail accomplish these tasks?
Social e-mail gets more from the social sharing such as "share to social" or "share with your network," which provides great insights to identify the members who frequently share your content. In this way, you can target customers more effectively.
Also, E-mail sign-up widgets on your social media pages can help you identify the top social networks with which your subscribers engage. You can use this data to optimize your digital marketing activities and enhance your customers’ engagement based on network popularity.

To summarize, using the information of the social e-mail subscribers you can engage more customers and increase loyalty and customer lifetime value.