In it’s most basic terms, marketing is the act of trying to get people to care about your business. Get them to care enough and they just might buy. The problem is finding enough people to care when no one cares. Clay Shirky in Here Comes Everybody:

Having a handful of people highly motivated and a mass of barely motivated ones used to be a recipe for frustration. The people who were on fire wondered why the general population didn’t care more, and the general population wondered why these obsessed people didn’t just shut up.

This is because:

The number of people who are willing to start something is smaller, much smaller, than the number of people who are willing to contribute once someone else starts something. Many people care a little about causes and events, but not many care enough to do anything about it on their own,  both because that kind of effort is hard and because individual actions have so little effect on big corporations.

But that’s now OK because:

Social media lowers the hurdles to doing something in the first place, so that people who cared a little could participate a little, while being effective in aggregate.

This is important in marketing your business on the internet because:

Now the highly motivated people can create a context more easily in which the barely motivated people can be effective without having to become activities themselves.

Get those less than loyal customers to engage with you, even if it is a little bit. Social media marketing allows your little brand to have a chance. Every extra person is another drop in the bucket that helps your idea to spread.