I have an Amazon Niche Site that is looking promising in the SERPs. I already have many keywords and long tails on page 2 and 3 without building any link. Some people say social media can help in ranking and initial traffic. My niche is about a baby toy. How do I start getting social media presence? Must I set up pages specifically for the website or can I ask established social media pages to post links to my website for a fee? Any help will be appreciated.