Google has confirmed that they do take social signals into consideration when they rank their websites. Taking this into consideration, Twittercan directly affect how your website is positioned in terms of Google’s search option. Getting active on Twitter is the first step to achieving a high Google ranking, one must also connect with relevant friends and industry peers, enter conversations, respond to questions and queries and talk to customers who mention your brand and interact.
Twitter must be used as a social tool if you want it to work best for your brand. In addition, if you want people to retweet your articles and content you will have a wider range of success if you are being followed by relevant peers and making an effort to maintain and nurture those relationships.
Via Pascal Gibert