People tend to have their favorite places to hang out, get news and information, and stay in touch with people in their communities. When it comes to search, Google is no longer the first place people go when seeking. Instead, they are equally likely to ask for recommendations or browse previous recommendations from people they know and trust within their community.
This is why social media marketing is important. Viral loops occur when people interact online, put out information, reach out to others in their community, and draw them into their circle.
Social media marketing is as important, if not more, than search engine optimization if you are trying to reach new people, generate leads, develop your brand, and market your products and services.