The old school link building tactics involved getting your links anywhere, even if those sites had little to no activity. Social media allows you to put your website and brand directly in front of potential customers. Produce good quality content and share it across social media and watch others interact and share it as well.
This is where the “social” part comes into play. Don’t just put it out there and hope it gets picked up. Interact with your social following and get them involved. When they feel involved and truly connected to your brand it results in sharing on a regular basis. While it can be hard, make sure to dedicate time each day to social interaction.