As said above, when you bookmark your website on FB, G+, twitter and so on, it will get indexed faster (supposedly).

If you listen to officials, social signals are not a ranking factor, or at least not directly.  But they do take a part of the algorithm in another way.

What do I mean? Every time you … Read more

It helps you build brand awareness. You shouldn't think of social marketing as direct sales as it would rarely be the case. But it can partially replace advertisement (actually you should advertise via social media), it will give you a direct interaction with future customers/clients and mainly it will build a name for your business.