Email Marketing vs Social Media

[batman]

Social media marketing is a quick process. You promote your brand to your customers and maybe gather leads from those leads, that's the whole idea of social media marketing. Email marketing is a bit different. You just can not simply mail random people. Random mailing might hurt your brand reputation. That's why mail is a formal approach. Email marketing is more effective for business to business approach. For a business to consumer social media is a quite good choice.  
I have read a blog on ADN Emails blog about this topic. They have a strong point on this topic.

That is correct . Email Marketing is direct but the others are not.